2161251157536 has 240 divisors, whose sum is σ = 6861248856000. Its totient is φ = 665332157952.

The previous prime is 2161251157489. The next prime is 2161251157577. The reversal of 2161251157536 is 6357511521612.

2161251157536 is a `hidden beast` number, since 2 + 1 + 6 + 12 + 51 + 1 + 57 + 536 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 2161251157491 and 2161251157500.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 1103815 + ... + 2353913.

It is an arithmetic number, because the mean of its divisors is an integer number (28588536900).

Almost surely, 2^{2161251157536} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 2161251157536, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3430624428000).

2161251157536 is an abundant number, since it is smaller than the sum of its proper divisors (4699997698464).

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

2161251157536 is a wasteful number, since it uses less digits than its factorization.

2161251157536 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1250173 (or 1250156 counting only the distinct ones).

The product of its digits is 378000, while the sum is 45.

The spelling of 2161251157536 in words is "two trillion, one hundred sixty-one billion, two hundred fifty-one million, one hundred fifty-seven thousand, five hundred thirty-six".