21958404 has 24 divisors (see below), whose sum is σ = 55177920. Its totient is φ = 6756384.

The previous prime is 21958403. The next prime is 21958421. The reversal of 21958404 is 40485912.

It is not an unprimeable number, because it can be changed into a prime (21958403) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 70224 + ... + 70535.

It is an arithmetic number, because the mean of its divisors is an integer number (2299080).

Almost surely, 2^21958404 is an apocalyptic number.

It is an amenable number.

21958404 is an abundant number, since it is smaller than the sum of its proper divisors (33219516).

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

21958404 is a wasteful number, since it uses less digits than its factorization.

21958404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140779 (or 140777 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 33.

The square root of 21958404 is about 4685.9795133995. The cubic root of 21958404 is about 280.0272252439.

The spelling of 21958404 in words is "twenty-one million, nine hundred fifty-eight thousand, four hundred four".