21958452 has 144 divisors (see below), whose sum is σ = 64209600. Its totient is φ = 6531840.

The previous prime is 21958429. The next prime is 21958457. The reversal of 21958452 is 25485912.

21958452 is a `hidden beast` number, since 21 + 9 + 584 + 52 = 666.

It is a super-2 number, since 2×21958452² = 964347228472608, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21958457) 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 47 ways as a sum of consecutive naturals, for example, 535552 + ... + 535592.

It is an arithmetic number, because the mean of its divisors is an integer number (445900).

Almost surely, 2^21958452 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 21958452, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32104800).

21958452 is an abundant number, since it is smaller than the sum of its proper divisors (42251148).

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

21958452 is a wasteful number, since it uses less digits than its factorization.

21958452 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 108 (or 94 counting only the distinct ones).

The product of its digits is 28800, while the sum is 36.

The square root of 21958452 is about 4685.9846350580. The cubic root of 21958452 is about 280.0274292857.

The spelling of 21958452 in words is "twenty-one million, nine hundred fifty-eight thousand, four hundred fifty-two".