2161399828900 has 243 divisors, whose sum is σ = 5219481562659. Its totient is φ = 776532032640.

The previous prime is 2161399828883. The next prime is 2161399828949. The reversal of 2161399828900 is 98289931612.

The square root of 2161399828900 is 1470170.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 557104003236 + 1604295825664 = 746394^2 + 1266608^2 .

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 8218250169 + ... + 8218250431.

Almost surely, 2^{2161399828900} is an apocalyptic number.

2161399828900 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

2161399828900 is the 1470170-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2161399828900

2161399828900 is an abundant number, since it is smaller than the sum of its proper divisors (3058081733759).

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

2161399828900 is a wasteful number, since it uses less digits than its factorization.

2161399828900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 652 (or 326 counting only the distinct ones).

The product of its (nonzero) digits is 3359232, while the sum is 58.

The spelling of 2161399828900 in words is "two trillion, one hundred sixty-one billion, three hundred ninety-nine million, eight hundred twenty-eight thousand, nine hundred".