21610372 has 48 divisors (see below), whose sum is σ = 46480000. Its totient is φ = 8763552.

The previous prime is 21610361. The next prime is 21610373. The reversal of 21610372 is 27301612.

It is not an unprimeable number, because it can be changed into a prime (21610373) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25654 + ... + 26482.

Almost surely, 2^21610372 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21610372, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23240000).

21610372 is an abundant number, since it is smaller than the sum of its proper divisors (24869628).

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

21610372 is a wasteful number, since it uses less digits than its factorization.

21610372 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 873 (or 857 counting only the distinct ones).

The product of its (nonzero) digits is 504, while the sum is 22.

The square root of 21610372 is about 4648.6957310626. The cubic root of 21610372 is about 278.5398993276.

Adding to 21610372 its reverse (27301612), we get a palindrome (48911984).

The spelling of 21610372 in words is "twenty-one million, six hundred ten thousand, three hundred seventy-two".