20870156657 has 8 divisors (see below), whose sum is σ = 23882469696. Its totient is φ = 17865559152.

The previous prime is 20870156647. The next prime is 20870156669. The reversal of 20870156657 is 75665107802.

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

It is not a de Polignac number, because 20870156657 - 2¹⁴ = 20870140273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20870156647) 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, 1923083 + ... + 1933904.

It is an arithmetic number, because the mean of its divisors is an integer number (2985308712).

Almost surely, 2^20870156657 is an apocalyptic number.

It is an amenable number.

20870156657 is a deficient number, since it is larger than the sum of its proper divisors (3012313039).

20870156657 is an equidigital number, since it uses as much as digits as its factorization.

20870156657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3857767.

The product of its (nonzero) digits is 705600, while the sum is 47.

The spelling of 20870156657 in words is "twenty billion, eight hundred seventy million, one hundred fifty-six thousand, six hundred fifty-seven".