21165950 has 24 divisors (see below), whose sum is σ = 42398328. Its totient is φ = 7814880.

The previous prime is 21165941. The next prime is 21165967. The reversal of 21165950 is 5956112.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 15632 + ... + 16931.

It is an arithmetic number, because the mean of its divisors is an integer number (1766597).

Almost surely, 2^21165950 is an apocalyptic number.

21165950 is an abundant number, since it is smaller than the sum of its proper divisors (21232378).

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

21165950 is a wasteful number, since it uses less digits than its factorization.

21165950 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32588 (or 32583 counting only the distinct ones).

The product of its (nonzero) digits is 2700, while the sum is 29.

The square root of 21165950 is about 4600.6466936725. The cubic root of 21165950 is about 276.6172473463.

It can be divided in two parts, 211 and 65950, that multiplied together give a triangular number (13915450 = T₅₂₇₅).

The spelling of 21165950 in words is "twenty-one million, one hundred sixty-five thousand, nine hundred fifty".