21519954 has 24 divisors (see below), whose sum is σ = 46912320. Its totient is φ = 7129368.

The previous prime is 21519929. The next prime is 21520003. The reversal of 21519954 is 45991512.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 574 + ... + 6585.

It is an arithmetic number, because the mean of its divisors is an integer number (1954680).

Almost surely, 2^21519954 is an apocalyptic number.

21519954 is an abundant number, since it is smaller than the sum of its proper divisors (25392366).

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

21519954 is a wasteful number, since it uses less digits than its factorization.

21519954 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7334 (or 7331 counting only the distinct ones).

The product of its digits is 16200, while the sum is 36.

The square root of 21519954 is about 4638.9604438926. The cubic root of 21519954 is about 278.1508850882.

The spelling of 21519954 in words is "twenty-one million, five hundred nineteen thousand, nine hundred fifty-four".