20740857 has 8 divisors (see below), whose sum is σ = 27681984. Its totient is φ = 13813488.

The previous prime is 20740849. The next prime is 20740873. The reversal of 20740857 is 75804702.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20740857 - 2³ = 20740849 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20740877) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 843 + ... + 6495.

It is an arithmetic number, because the mean of its divisors is an integer number (3460248).

Almost surely, 2^20740857 is an apocalyptic number.

It is an amenable number.

20740857 is a deficient number, since it is larger than the sum of its proper divisors (6941127).

20740857 is a wasteful number, since it uses less digits than its factorization.

20740857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6879.

The product of its (nonzero) digits is 15680, while the sum is 33.

The square root of 20740857 is about 4554.2131043683. The cubic root of 20740857 is about 274.7528666813.

The spelling of 20740857 in words is "twenty million, seven hundred forty thousand, eight hundred fifty-seven".