2645216431561 has 16 divisors (see below), whose sum is σ = 2986114947840. Its totient is φ = 2321106282880.

The previous prime is 2645216431549. The next prime is 2645216431591. The reversal of 2645216431561 is 1651346125462.

It is not a de Polignac number, because 2645216431561 - 2⁹ = 2645216431049 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2645216431591) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 234001 + ... + 2311966.

It is an arithmetic number, because the mean of its divisors is an integer number (186632184240).

Almost surely, 2^{2645216431561} is an apocalyptic number.

It is an amenable number.

2645216431561 is a deficient number, since it is larger than the sum of its proper divisors (340898516279).

2645216431561 is a wasteful number, since it uses less digits than its factorization.

2645216431561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2549264.

The product of its digits is 1036800, while the sum is 46.

The spelling of 2645216431561 in words is "two trillion, six hundred forty-five billion, two hundred sixteen million, four hundred thirty-one thousand, five hundred sixty-one".