21894970 has 16 divisors (see below), whose sum is σ = 39465000. Its totient is φ = 8745984.

The previous prime is 21894967. The next prime is 21894991. The reversal of 21894970 is 7949812.

It can be written as a sum of positive squares in 4 ways, for example, as 10246401 + 11648569 = 3201^2 + 3413^2 .

It is a super-2 number, since 2×21894970² = 958779422601800, which contains 22 as substring.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 11614 + ... + 13366.

Almost surely, 2^21894970 is an apocalyptic number.

21894970 is a deficient number, since it is larger than the sum of its proper divisors (17570030).

21894970 is a wasteful number, since it uses less digits than its factorization.

21894970 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3009.

The product of its (nonzero) digits is 36288, while the sum is 40.

The square root of 21894970 is about 4679.2061292488. The cubic root of 21894970 is about 279.7573152285.

The spelling of 21894970 in words is "twenty-one million, eight hundred ninety-four thousand, nine hundred seventy".