21160764 has 60 divisors (see below), whose sum is σ = 55752928. Its totient is φ = 6998400.

The previous prime is 21160747. The next prime is 21160771. The reversal of 21160764 is 46706112.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 77949 + ... + 78219.

Almost surely, 2^21160764 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21160764, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27876464).

21160764 is an abundant number, since it is smaller than the sum of its proper divisors (34592164).

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

21160764 is a wasteful number, since it uses less digits than its factorization.

21160764 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 528 (or 517 counting only the distinct ones).

The product of its (nonzero) digits is 2016, while the sum is 27.

The square root of 21160764 is about 4600.0830427287. The cubic root of 21160764 is about 276.5946536015.

Adding to 21160764 its reverse (46706112), we get a palindrome (67866876).

The spelling of 21160764 in words is "twenty-one million, one hundred sixty thousand, seven hundred sixty-four".