20720986 has 32 divisors (see below), whose sum is σ = 37231488. Its totient is φ = 8523840.

The previous prime is 20720971. The next prime is 20721013. The reversal of 20720986 is 68902702.

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, 14475 + ... + 15841.

It is an arithmetic number, because the mean of its divisors is an integer number (1163484).

Almost surely, 2^20720986 is an apocalyptic number.

20720986 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

20720986 is a deficient number, since it is larger than the sum of its proper divisors (16510502).

20720986 is a wasteful number, since it uses less digits than its factorization.

20720986 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1446.

The product of its (nonzero) digits is 12096, while the sum is 34.

The square root of 20720986 is about 4552.0309752900. The cubic root of 20720986 is about 274.6650953372.

The spelling of 20720986 in words is "twenty million, seven hundred twenty thousand, nine hundred eighty-six".