21379850 has 12 divisors (see below), whose sum is σ = 39766614. Its totient is φ = 8551920.

The previous prime is 21379837. The next prime is 21379879. The reversal of 21379850 is 5897312.

It can be written as a sum of positive squares in 3 ways, for example, as 17581249 + 3798601 = 4193^2 + 1949^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21379850.

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 5 ways as a sum of consecutive naturals, for example, 213749 + ... + 213848.

Almost surely, 2^21379850 is an apocalyptic number.

21379850 is a deficient number, since it is larger than the sum of its proper divisors (18386764).

21379850 is a wasteful number, since it uses less digits than its factorization.

21379850 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 427609 (or 427604 counting only the distinct ones).

The product of its (nonzero) digits is 15120, while the sum is 35.

The square root of 21379850 is about 4623.8349884052. The cubic root of 21379850 is about 277.5459437498.

The spelling of 21379850 in words is "twenty-one million, three hundred seventy-nine thousand, eight hundred fifty".