7871561658 has 36 divisors (see below), whose sum is σ = 17220115770. Its totient is φ = 2598483888.

The previous prime is 7871561651. The next prime is 7871561681. The reversal of 7871561658 is 8561651787.

7871561658 is a `hidden beast` number, since 7 + 8 + 7 + 15 + 616 + 5 + 8 = 666.

It can be written as a sum of positive squares in only one way, i.e., 6102265689 + 1769295969 = 78117^2 + 42063^2 .

It is a super-2 number, since 2×7871561658² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (7871561651) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 3928885 + ... + 3930887.

Almost surely, 2^7871561658 is an apocalyptic number.

7871561658 is an abundant number, since it is smaller than the sum of its proper divisors (9348554112).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

7871561658 is a wasteful number, since it uses less digits than its factorization.

7871561658 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4123 (or 2117 counting only the distinct ones).

The product of its digits is 2822400, while the sum is 54.

The square root of 7871561658 is about 88721.8217689425. The cubic root of 7871561658 is about 1989.2390092146.

The spelling of 7871561658 in words is "seven billion, eight hundred seventy-one million, five hundred sixty-one thousand, six hundred fifty-eight".