20000657 has 4 divisors (see below), whose sum is σ = 20010276. Its totient is φ = 19991040.

The previous prime is 20000641. The next prime is 20000671. The reversal of 20000657 is 75600002.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 19704721 + 295936 = 4439^2 + 544^2 .

It is a cyclic number.

It is not a de Polignac number, because 20000657 - 2⁴ = 20000641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20008657) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 248 + ... + 6329.

It is an arithmetic number, because the mean of its divisors is an integer number (5002569).

Almost surely, 2^20000657 is an apocalyptic number.

It is an amenable number.

20000657 is a deficient number, since it is larger than the sum of its proper divisors (9619).

20000657 is an equidigital number, since it uses as much as digits as its factorization.

20000657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9618.

The product of its (nonzero) digits is 420, while the sum is 20.

The square root of 20000657 is about 4472.2094092294. The cubic root of 20000657 is about 271.4447339142. Note that the first 3 decimals are identical.

Adding to 20000657 its reverse (75600002), we get a palindrome (95600659).

The spelling of 20000657 in words is "twenty million, six hundred fifty-seven", and thus it is an aban number.