21623352 has 16 divisors (see below), whose sum is σ = 54058440. Its totient is φ = 7207776.

The previous prime is 21623347. The next prime is 21623353. The reversal of 21623352 is 25332612.

It is a Harshad number since it is a multiple of its sum of digits (24), and also a Moran number because the ratio is a prime number: 900973 = 21623352 / (2 + 1 + 6 + 2 + 3 + 3 + 5 + 2).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21623353) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 450463 + ... + 450510.

Almost surely, 2^21623352 is an apocalyptic number.

It is an amenable number.

21623352 is an abundant number, since it is smaller than the sum of its proper divisors (32435088).

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

21623352 is a wasteful number, since it uses less digits than its factorization.

21623352 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 900982 (or 900978 counting only the distinct ones).

The product of its digits is 2160, while the sum is 24.

The square root of 21623352 is about 4650.0916120008. The cubic root of 21623352 is about 278.5956553364.

Adding to 21623352 its reverse (25332612), we get a palindrome (46955964).

The spelling of 21623352 in words is "twenty-one million, six hundred twenty-three thousand, three hundred fifty-two".