21102704 has 20 divisors (see below), whose sum is σ = 46727664. Its totient is φ = 9043968.

The previous prime is 21102677. The next prime is 21102709. The reversal of 21102704 is 40720112.

It is a super-2 number, since 2×21102704² = 890648232223232, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21102709) 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, 94097 + ... + 94320.

Almost surely, 2^21102704 is an apocalyptic number.

It is an amenable number.

21102704 is an abundant number, since it is smaller than the sum of its proper divisors (25624960).

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

21102704 is a wasteful number, since it uses less digits than its factorization.

21102704 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 188432 (or 188426 counting only the distinct ones).

The product of its (nonzero) digits is 112, while the sum is 17.

The square root of 21102704 is about 4593.7679523459. The cubic root of 21102704 is about 276.3414523556.

Adding to 21102704 its reverse (40720112), we get a palindrome (61822816).

The spelling of 21102704 in words is "twenty-one million, one hundred two thousand, seven hundred four".