2157121138899 has 8 divisors (see below), whose sum is σ = 3027538440640. Its totient is φ = 1362392298216.

The previous prime is 2157121138897. The next prime is 2157121138927. The reversal of 2157121138899 is 9988311217512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 2157121138899 - 2¹ = 2157121138897 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (57), and also a Moran number because the ratio is a prime number: 37844230507 = 2157121138899 / (2 + 1 + 5 + 7 + 1 + 2 + 1 + 1 + 3 + 8 + 8 + 9 + 9).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2157121138897) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18922115197 + ... + 18922115310.

It is an arithmetic number, because the mean of its divisors is an integer number (378442305080).

Almost surely, 2^{2157121138899} is an apocalyptic number.

2157121138899 is a deficient number, since it is larger than the sum of its proper divisors (870417301741).

2157121138899 is a wasteful number, since it uses less digits than its factorization.

2157121138899 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 37844230529.

The product of its digits is 2177280, while the sum is 57.

The spelling of 2157121138899 in words is "two trillion, one hundred fifty-seven billion, one hundred twenty-one million, one hundred thirty-eight thousand, eight hundred ninety-nine".