21679770 has 32 divisors (see below), whose sum is σ = 59465088. Its totient is φ = 4955328.

The previous prime is 21679769. The next prime is 21679787. The reversal of 21679770 is 7797612.

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 15 ways as a sum of consecutive naturals, for example, 51409 + ... + 51828.

It is an arithmetic number, because the mean of its divisors is an integer number (1858284).

Almost surely, 2^21679770 is an apocalyptic number.

21679770 is an abundant number, since it is smaller than the sum of its proper divisors (37785318).

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

21679770 is a wasteful number, since it uses less digits than its factorization.

21679770 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 103254.

The product of its (nonzero) digits is 37044, while the sum is 39.

The square root of 21679770 is about 4656.1539922988. The cubic root of 21679770 is about 278.8377417554.

The spelling of 21679770 in words is "twenty-one million, six hundred seventy-nine thousand, seven hundred seventy".