16561507201439 has 16 divisors (see below), whose sum is σ = 17823955101696. Its totient is φ = 15332104905600.

The previous prime is 16561507201433. The next prime is 16561507201471. The reversal of 16561507201439 is 93410270516561.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16561507201439 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16561507201433) 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, 15397667 + ... + 16438100.

It is an arithmetic number, because the mean of its divisors is an integer number (1113997193856).

Almost surely, 2^{16561507201439} is an apocalyptic number.

16561507201439 is a deficient number, since it is larger than the sum of its proper divisors (1262447900257).

16561507201439 is a wasteful number, since it uses less digits than its factorization.

16561507201439 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31836286.

The product of its (nonzero) digits is 1360800, while the sum is 50.

The spelling of 16561507201439 in words is "sixteen trillion, five hundred sixty-one billion, five hundred seven million, two hundred one thousand, four hundred thirty-nine".