Search a number
-
+
21100040 = 2351340577
BaseRepresentation
bin101000001111…
…1011000001000
31110200222210222
41100133120020
520400200130
62032125212
7344230103
oct120373010
943628728
1021100040
1110a01855
127096808
1344aa040
142b3373a
151cbbce5
hex141f608

21100040 has 32 divisors (see below), whose sum is σ = 51128280. Its totient is φ = 7790592.

The previous prime is 21100033. The next prime is 21100049. The reversal of 21100040 is 4000112.

It can be written as a sum of positive squares in 4 ways, for example, as 14577124 + 6522916 = 3818^2 + 2554^2 .

It is a Harshad number since it is a multiple of its sum of digits (8).

It is not an unprimeable number, because it can be changed into a prime (21100049) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19769 + ... + 20808.

Almost surely, 221100040 is an apocalyptic number.

21100040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21100040 is an abundant number, since it is smaller than the sum of its proper divisors (30028240).

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

21100040 is a wasteful number, since it uses less digits than its factorization.

21100040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40601 (or 40597 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 8.

The square root of 21100040 is about 4593.4779851437. The cubic root of 21100040 is about 276.3298234412.

Adding to 21100040 its reverse (4000112), we get a palindrome (25100152).

The spelling of 21100040 in words is "twenty-one million, one hundred thousand, forty".

Divisors: 1 2 4 5 8 10 13 20 26 40 52 65 104 130 260 520 40577 81154 162308 202885 324616 405770 527501 811540 1055002 1623080 2110004 2637505 4220008 5275010 10550020 21100040