20675640 has 32 divisors (see below), whose sum is σ = 62027280. Its totient is φ = 5513472.

The previous prime is 20675639. The next prime is 20675653. The reversal of 20675640 is 4657602.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 20675598 and 20675607.

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, 86029 + ... + 86268.

Almost surely, 2^20675640 is an apocalyptic number.

20675640 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

20675640 is an abundant number, since it is smaller than the sum of its proper divisors (41351640).

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

20675640 is a wasteful number, since it uses less digits than its factorization.

20675640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172311 (or 172307 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 30.

The square root of 20675640 is about 4547.0473936391. The cubic root of 20675640 is about 274.4645891130.

The spelling of 20675640 in words is "twenty million, six hundred seventy-five thousand, six hundred forty".