21906770 has 16 divisors (see below), whose sum is σ = 40704768. Its totient is φ = 8479920.

The previous prime is 21906767. The next prime is 21906809. The reversal of 21906770 is 7760912.

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 7 ways as a sum of consecutive naturals, for example, 35024 + ... + 35643.

It is an arithmetic number, because the mean of its divisors is an integer number (2544048).

Almost surely, 2^21906770 is an apocalyptic number.

21906770 is a deficient number, since it is larger than the sum of its proper divisors (18797998).

21906770 is a wasteful number, since it uses less digits than its factorization.

21906770 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70705.

The product of its (nonzero) digits is 5292, while the sum is 32.

The square root of 21906770 is about 4680.4668570560. The cubic root of 21906770 is about 279.8075633519.

The spelling of 21906770 in words is "twenty-one million, nine hundred six thousand, seven hundred seventy".