2161204544520 has 128 divisors (see below), whose sum is σ = 8233160198400. Its totient is φ = 493989608448.

The previous prime is 2161204544507. The next prime is 2161204544539. The reversal of 2161204544520 is 254454021612.

2161204544520 is a `hidden beast` number, since 2 + 1 + 6 + 1 + 204 + 5 + 445 + 2 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 142929249 + ... + 142944368.

It is an arithmetic number, because the mean of its divisors is an integer number (64321564050).

Almost surely, 2^{2161204544520} is an apocalyptic number.

2161204544520 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

2161204544520 is an abundant number, since it is smaller than the sum of its proper divisors (6071955653880).

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

2161204544520 is a wasteful number, since it uses less digits than its factorization.

2161204544520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 285873644 (or 285873634 counting only the distinct ones).

The product of its (nonzero) digits is 76800, while the sum is 36.

The spelling of 2161204544520 in words is "two trillion, one hundred sixty-one billion, two hundred four million, five hundred forty-four thousand, five hundred twenty".