21270764 has 12 divisors (see below), whose sum is σ = 37257024. Its totient is φ = 10625904.

The previous prime is 21270763. The next prime is 21270773. The reversal of 21270764 is 46707212.

It is a super-2 number, since 2×21270764² = 904890802287392, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21270763) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5834 + ... + 8750.

It is an arithmetic number, because the mean of its divisors is an integer number (3104752).

Almost surely, 2^21270764 is an apocalyptic number.

It is an amenable number.

21270764 is a deficient number, since it is larger than the sum of its proper divisors (15986260).

21270764 is a wasteful number, since it uses less digits than its factorization.

21270764 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4744 (or 4742 counting only the distinct ones).

The product of its (nonzero) digits is 4704, while the sum is 29.

The square root of 21270764 is about 4612.0238507623. The cubic root of 21270764 is about 277.0730995196.

Adding to 21270764 its reverse (46707212), we get a palindrome (67977976).

The spelling of 21270764 in words is "twenty-one million, two hundred seventy thousand, seven hundred sixty-four".