21136040 has 16 divisors (see below), whose sum is σ = 47556180. Its totient is φ = 8454400.

The previous prime is 21136039. The next prime is 21136067. The reversal of 21136040 is 4063112.

It can be written as a sum of positive squares in 2 ways, for example, as 20016676 + 1119364 = 4474^2 + 1058^2 .

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, 264161 + ... + 264240.

Almost surely, 2^21136040 is an apocalyptic number.

21136040 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21136040 is an abundant number, since it is smaller than the sum of its proper divisors (26420140).

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

21136040 is a wasteful number, since it uses less digits than its factorization.

21136040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 528412 (or 528408 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 17.

The square root of 21136040 is about 4597.3949145141. The cubic root of 21136040 is about 276.4868882533.

Adding to 21136040 its reverse (4063112), we get a palindrome (25199152).

The spelling of 21136040 in words is "twenty-one million, one hundred thirty-six thousand, forty".