20642740 has 24 divisors (see below), whose sum is σ = 45632160. Its totient is φ = 7822368.

The previous prime is 20642731. The next prime is 20642773. The reversal of 20642740 is 4724602.

It is a super-2 number, since 2×20642740² = 852245429415200, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 26782 + ... + 27541.

It is an arithmetic number, because the mean of its divisors is an integer number (1901340).

Almost surely, 2^20642740 is an apocalyptic number.

20642740 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20642740 is an abundant number, since it is smaller than the sum of its proper divisors (24989420).

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

20642740 is a wasteful number, since it uses less digits than its factorization.

20642740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54351 (or 54349 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 25.

The square root of 20642740 is about 4543.4282210683. The cubic root of 20642740 is about 274.3189317306.

The spelling of 20642740 in words is "twenty million, six hundred forty-two thousand, seven hundred forty".