21439292 has 24 divisors (see below), whose sum is σ = 43160544. Its totient is φ = 9127872.

The previous prime is 21439291. The next prime is 21439307. The reversal of 21439292 is 29293412.

It is a super-2 number, since 2×21439292² = 919286482922528, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21439291) 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, 1958 + ... + 6834.

It is an arithmetic number, because the mean of its divisors is an integer number (1798356).

Almost surely, 2^21439292 is an apocalyptic number.

It is an amenable number.

21439292 is an abundant number, since it is smaller than the sum of its proper divisors (21721252).

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

21439292 is a wasteful number, since it uses less digits than its factorization.

21439292 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5045 (or 5043 counting only the distinct ones).

The product of its digits is 7776, while the sum is 32.

The square root of 21439292 is about 4630.2583081293. The cubic root of 21439292 is about 277.8029243487.

The spelling of 21439292 in words is "twenty-one million, four hundred thirty-nine thousand, two hundred ninety-two".