21371949 has 12 divisors (see below), whose sum is σ = 31262400. Its totient is φ = 14067144.

The previous prime is 21371929. The next prime is 21371963. The reversal of 21371949 is 94917312.

It is not a de Polignac number, because 21371949 - 2⁷ = 21371821 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21371929) 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 11 ways as a sum of consecutive naturals, for example, 14319 + ... + 15740.

It is an arithmetic number, because the mean of its divisors is an integer number (2605200).

Almost surely, 2^21371949 is an apocalyptic number.

It is an amenable number.

21371949 is a deficient number, since it is larger than the sum of its proper divisors (9890451).

21371949 is a wasteful number, since it uses less digits than its factorization.

21371949 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30144 (or 30141 counting only the distinct ones).

The product of its digits is 13608, while the sum is 36.

The square root of 21371949 is about 4622.9805320810. The cubic root of 21371949 is about 277.5117501720.

The spelling of 21371949 in words is "twenty-one million, three hundred seventy-one thousand, nine hundred forty-nine".