2161651646642 has 4 divisors (see below), whose sum is σ = 3242477469966. Its totient is φ = 1080825823320.

The previous prime is 2161651646629. The next prime is 2161651646657. The reversal of 2161651646642 is 2466461561612.

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., 2110363438681 + 51288207961 = 1452709^2 + 226469^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 540412911659 + ... + 540412911662.

Almost surely, 2^{2161651646642} is an apocalyptic number.

2161651646642 is a deficient number, since it is larger than the sum of its proper divisors (1080825823324).

2161651646642 is a wasteful number, since it uses less digits than its factorization.

2161651646642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1080825823323.

The product of its digits is 2488320, while the sum is 50.

The spelling of 2161651646642 in words is "two trillion, one hundred sixty-one billion, six hundred fifty-one million, six hundred forty-six thousand, six hundred forty-two".