2157918601 has 4 divisors (see below), whose sum is σ = 2210550804. Its totient is φ = 2105286400.

The previous prime is 2157918593. The next prime is 2157918643. The reversal of 2157918601 is 1068197512.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 968703376 + 1189215225 = 31124^2 + 34485^2 .

It is a cyclic number.

It is not a de Polignac number, because 2157918601 - 2³ = 2157918593 is a prime.

It is a super-2 number, since 2×2157918601² = 9313225377083594402, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2157913601) 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, 26316040 + ... + 26316121.

It is an arithmetic number, because the mean of its divisors is an integer number (552637701).

Almost surely, 2^2157918601 is an apocalyptic number.

It is an amenable number.

2157918601 is a deficient number, since it is larger than the sum of its proper divisors (52632203).

2157918601 is an equidigital number, since it uses as much as digits as its factorization.

2157918601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 52632202.

The product of its (nonzero) digits is 30240, while the sum is 40.

The square root of 2157918601 is about 46453.4024695716. The cubic root of 2157918601 is about 1292.2454733400.

The spelling of 2157918601 in words is "two billion, one hundred fifty-seven million, nine hundred eighteen thousand, six hundred one".