21070536 has 16 divisors (see below), whose sum is σ = 52676400. Its totient is φ = 7023504.

The previous prime is 21070513. The next prime is 21070541. The reversal of 21070536 is 63507012.

It is a Harshad number since it is a multiple of its sum of digits (24), and also a Moran number because the ratio is a prime number: 877939 = 21070536 / (2 + 1 + 0 + 7 + 0 + 5 + 3 + 6).

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 438946 + ... + 438993.

It is an arithmetic number, because the mean of its divisors is an integer number (3292275).

Almost surely, 2^21070536 is an apocalyptic number.

It is an amenable number.

21070536 is an abundant number, since it is smaller than the sum of its proper divisors (31605864).

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

21070536 is a wasteful number, since it uses less digits than its factorization.

21070536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 877948 (or 877944 counting only the distinct ones).

The product of its (nonzero) digits is 1260, while the sum is 24.

The square root of 21070536 is about 4590.2653518070. The cubic root of 21070536 is about 276.2009668438.

Adding to 21070536 its reverse (63507012), we get a palindrome (84577548).

The spelling of 21070536 in words is "twenty-one million, seventy thousand, five hundred thirty-six".