21521292 has 24 divisors (see below), whose sum is σ = 54079536. Its totient is φ = 6621888.

The previous prime is 21521263. The next prime is 21521299. The reversal of 21521292 is 29212512.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21521299) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 68823 + ... + 69134.

It is an arithmetic number, because the mean of its divisors is an integer number (2253314).

Almost surely, 2^21521292 is an apocalyptic number.

It is an amenable number.

21521292 is an abundant number, since it is smaller than the sum of its proper divisors (32558244).

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

21521292 is a wasteful number, since it uses less digits than its factorization.

21521292 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 137977 (or 137975 counting only the distinct ones).

The product of its digits is 720, while the sum is 24.

The square root of 21521292 is about 4639.1046549954. The cubic root of 21521292 is about 278.1566496323.

The spelling of 21521292 in words is "twenty-one million, five hundred twenty-one thousand, two hundred ninety-two".