20640702 has 16 divisors (see below), whose sum is σ = 41746320. Its totient is φ = 6802752.

The previous prime is 20640679. The next prime is 20640713. The reversal of 20640702 is 20704602.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18793 + ... + 19860.

It is an arithmetic number, because the mean of its divisors is an integer number (2609145).

Almost surely, 2^20640702 is an apocalyptic number.

20640702 is an abundant number, since it is smaller than the sum of its proper divisors (21105618).

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

20640702 is a wasteful number, since it uses less digits than its factorization.

20640702 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38747.

The product of its (nonzero) digits is 672, while the sum is 21.

The square root of 20640702 is about 4543.2039355503. The cubic root of 20640702 is about 274.3099038531.

The spelling of 20640702 in words is "twenty million, six hundred forty thousand, seven hundred two".