21903970 has 32 divisors (see below), whose sum is σ = 43436736. Its totient is φ = 7886400.

The previous prime is 21903943. The next prime is 21903983. The reversal of 21903970 is 7930912.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10840 + ... + 12700.

It is an arithmetic number, because the mean of its divisors is an integer number (1357398).

Almost surely, 2^21903970 is an apocalyptic number.

21903970 is a deficient number, since it is larger than the sum of its proper divisors (21532766).

21903970 is a wasteful number, since it uses less digits than its factorization.

21903970 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1986.

The product of its (nonzero) digits is 3402, while the sum is 31.

The square root of 21903970 is about 4680.1677320370. The cubic root of 21903970 is about 279.7956417015.

The spelling of 21903970 in words is "twenty-one million, nine hundred three thousand, nine hundred seventy".