20356857 has 12 divisors (see below), whose sum is σ = 29680560. Its totient is φ = 13443768.

The previous prime is 20356841. The next prime is 20356873. The reversal of 20356857 is 75865302.

It is an interprime number because it is at equal distance from previous prime (20356841) and next prime (20356873).

It is not a de Polignac number, because 20356857 - 2⁴ = 20356841 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20356807) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9607 + ... + 11532.

It is an arithmetic number, because the mean of its divisors is an integer number (2473380).

Almost surely, 2^20356857 is an apocalyptic number.

It is an amenable number.

20356857 is a deficient number, since it is larger than the sum of its proper divisors (9323703).

20356857 is a wasteful number, since it uses less digits than its factorization.

20356857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21252 (or 21249 counting only the distinct ones).

The product of its (nonzero) digits is 50400, while the sum is 36.

The square root of 20356857 is about 4511.8573780650. The cubic root of 20356857 is about 273.0466852495.

The spelling of 20356857 in words is "twenty million, three hundred fifty-six thousand, eight hundred fifty-seven".