2161563557625 has 24 divisors (see below), whose sum is σ = 3896578575240. Its totient is φ = 1152833896800.

The previous prime is 2161563557623. The next prime is 2161563557639. The reversal of 2161563557625 is 5267553651612.

2161563557625 is a `hidden beast` number, since 2 + 1 + 6 + 1 + 5 + 6 + 3 + 5 + 5 + 7 + 625 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 450008863929 + 1711554693696 = 670827^2 + 1308264^2 .

It is not a de Polignac number, because 2161563557625 - 2¹ = 2161563557623 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2161563557623) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 960693790 + ... + 960696039.

It is an arithmetic number, because the mean of its divisors is an integer number (162357440635).

Almost surely, 2^{2161563557625} is an apocalyptic number.

2161563557625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

2161563557625 is a deficient number, since it is larger than the sum of its proper divisors (1735015017615).

2161563557625 is a wasteful number, since it uses less digits than its factorization.

2161563557625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1921389850 (or 1921389837 counting only the distinct ones).

The product of its digits is 11340000, while the sum is 54.

The spelling of 2161563557625 in words is "two trillion, one hundred sixty-one billion, five hundred sixty-three million, five hundred fifty-seven thousand, six hundred twenty-five".