21629320 has 32 divisors (see below), whose sum is σ = 50238720. Its totient is φ = 8372160.

The previous prime is 21629303. The next prime is 21629327. The reversal of 21629320 is 2392612.

It is a happy number.

It is a plaindrome in base 11.

It is not an unprimeable number, because it can be changed into a prime (21629327) 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, 7482 + ... + 9961.

It is an arithmetic number, because the mean of its divisors is an integer number (1569960).

Almost surely, 2^21629320 is an apocalyptic number.

21629320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21629320 is an abundant number, since it is smaller than the sum of its proper divisors (28609400).

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

21629320 is a wasteful number, since it uses less digits than its factorization.

21629320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17485 (or 17481 counting only the distinct ones).

The product of its (nonzero) digits is 1296, while the sum is 25.

The square root of 21629320 is about 4650.7332755169. The cubic root of 21629320 is about 278.6212835851.

The spelling of 21629320 in words is "twenty-one million, six hundred twenty-nine thousand, three hundred twenty".