21634074 has 128 divisors (see below), whose sum is σ = 61839360. Its totient is φ = 5488560.

The previous prime is 21634073. The next prime is 21634079. The reversal of 21634074 is 47043612.

21634074 is a `hidden beast` number, since 21 + 634 + 0 + 7 + 4 = 666.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21634073) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 503097 + ... + 503139.

It is an arithmetic number, because the mean of its divisors is an integer number (483120).

Almost surely, 2^21634074 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21634074, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30919680).

21634074 is an abundant number, since it is smaller than the sum of its proper divisors (40205286).

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

21634074 is a wasteful number, since it uses less digits than its factorization.

21634074 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94 (or 66 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 27.

The square root of 21634074 is about 4651.2443496338. The cubic root of 21634074 is about 278.6416952077.

Adding to 21634074 its reverse (47043612), we get a palindrome (68677686).

The spelling of 21634074 in words is "twenty-one million, six hundred thirty-four thousand, seventy-four".