21201968 has 10 divisors (see below), whose sum is σ = 41078844. Its totient is φ = 10600976.

The previous prime is 21201937. The next prime is 21201979. The reversal of 21201968 is 86910212.

It is a self number, because there is not a number n which added to its sum of digits gives 21201968.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 662546 + ... + 662577.

Almost surely, 2^21201968 is an apocalyptic number.

It is an amenable number.

21201968 is a deficient number, since it is larger than the sum of its proper divisors (19876876).

21201968 is a wasteful number, since it uses less digits than its factorization.

21201968 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1325131 (or 1325125 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 29.

The square root of 21201968 is about 4604.5594794725. The cubic root of 21201968 is about 276.7740645285.

It can be divided in two parts, 21 and 201968, that multiplied together give a triangular number (4241328 = T₂₉₁₂).

The spelling of 21201968 in words is "twenty-one million, two hundred one thousand, nine hundred sixty-eight".