20661711 has 16 divisors (see below), whose sum is σ = 31766784. Its totient is φ = 11700864.

The previous prime is 20661703. The next prime is 20661727. The reversal of 20661711 is 11716602.

It is not a de Polignac number, because 20661711 - 2³ = 20661703 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20662711) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1981 + ... + 6726.

It is an arithmetic number, because the mean of its divisors is an integer number (1985424).

Almost surely, 2^20661711 is an apocalyptic number.

20661711 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

20661711 is a deficient number, since it is larger than the sum of its proper divisors (11105073).

20661711 is a wasteful number, since it uses less digits than its factorization.

20661711 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8830.

The product of its (nonzero) digits is 504, while the sum is 24.

The square root of 20661711 is about 4545.5154823188. The cubic root of 20661711 is about 274.4029404596.

The spelling of 20661711 in words is "twenty million, six hundred sixty-one thousand, seven hundred eleven".