21310552 has 48 divisors (see below), whose sum is σ = 43342560. Its totient is φ = 9816768.

The previous prime is 21310519. The next prime is 21310561. The reversal of 21310552 is 25501312.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 135658 + ... + 135814.

It is an arithmetic number, because the mean of its divisors is an integer number (902970).

Almost surely, 2^21310552 is an apocalyptic number.

It is an amenable number.

21310552 is an abundant number, since it is smaller than the sum of its proper divisors (22032008).

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

21310552 is a wasteful number, since it uses less digits than its factorization.

21310552 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 248 (or 225 counting only the distinct ones).

The product of its (nonzero) digits is 300, while the sum is 19.

The square root of 21310552 is about 4616.3353431050. The cubic root of 21310552 is about 277.2457514886.

Adding to 21310552 its reverse (25501312), we get a palindrome (46811864).

The spelling of 21310552 in words is "twenty-one million, three hundred ten thousand, five hundred fifty-two".