21919504 has 10 divisors (see below), whose sum is σ = 42469070. Its totient is φ = 10959744.

The previous prime is 21919501. The next prime is 21919507. The reversal of 21919504 is 40591912.

It is an interprime number because it is at equal distance from previous prime (21919501) and next prime (21919507).

It can be written as a sum of positive squares in only one way, i.e., 17305600 + 4613904 = 4160^2 + 2148^2 .

It is not an unprimeable number, because it can be changed into a prime (21919501) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 684969 + ... + 685000.

It is an arithmetic number, because the mean of its divisors is an integer number (4246907).

Almost surely, 2^21919504 is an apocalyptic number.

It is an amenable number.

21919504 is a deficient number, since it is larger than the sum of its proper divisors (20549566).

21919504 is a wasteful number, since it uses less digits than its factorization.

21919504 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1369977 (or 1369971 counting only the distinct ones).

The product of its (nonzero) digits is 3240, while the sum is 31.

The square root of 21919504 is about 4681.8269938134. The cubic root of 21919504 is about 279.8617685033.

The spelling of 21919504 in words is "twenty-one million, nine hundred nineteen thousand, five hundred four".