Search a number
-
+
21604590 = 2335722371
BaseRepresentation
bin101001001101…
…0100011101110
31111122121221000
41102122203232
521012321330
62051021130
7351431100
oct122324356
944577830
1021604590
1111216937
12729a7a6
1346258a7
142c25570
151d6b560
hex149a8ee

21604590 has 192 divisors, whose sum is σ = 70917120. Its totient is φ = 4656960.

The previous prime is 21604579. The next prime is 21604601. The reversal of 21604590 is 9540612.

21604590 is a `hidden beast` number, since 2 + 1 + 604 + 59 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (21604579) and next prime (21604601).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 304255 + ... + 304325.

It is an arithmetic number, because the mean of its divisors is an integer number (369360).

Almost surely, 221604590 is an apocalyptic number.

21604590 is the 2940-th heptagonal number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21604590, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35458560).

21604590 is an abundant number, since it is smaller than the sum of its proper divisors (49312530).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21604590 is a wasteful number, since it uses less digits than its factorization.

21604590 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 124 (or 111 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 21604590 is about 4648.0737945949. The cubic root of 21604590 is about 278.5150553722.

The spelling of 21604590 in words is "twenty-one million, six hundred four thousand, five hundred ninety".