2161531865074 has 4 divisors (see below), whose sum is σ = 3242297797614. Its totient is φ = 1080765932536.

The previous prime is 2161531865041. The next prime is 2161531865099. The reversal of 2161531865074 is 4705681351612.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 2140348518049 + 21183347025 = 1462993^2 + 145545^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 540382966267 + ... + 540382966270.

Almost surely, 2^{2161531865074} is an apocalyptic number.

2161531865074 is a deficient number, since it is larger than the sum of its proper divisors (1080765932540).

2161531865074 is a wasteful number, since it uses less digits than its factorization.

2161531865074 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1080765932539.

The product of its (nonzero) digits is 1209600, while the sum is 49.

The spelling of 2161531865074 in words is "two trillion, one hundred sixty-one billion, five hundred thirty-one million, eight hundred sixty-five thousand, seventy-four".