61564646517 has 32 divisors (see below), whose sum is σ = 91138560000. Its totient is φ = 36654171840.

The previous prime is 61564646513. The next prime is 61564646519. The reversal of 61564646517 is 71564646516.

It is not a de Polignac number, because 61564646517 - 2² = 61564646513 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 61564646517.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61564646513) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 459459 + ... + 578127.

It is an arithmetic number, because the mean of its divisors is an integer number (2848080000).

Almost surely, 2^61564646517 is an apocalyptic number.

It is an amenable number.

61564646517 is a deficient number, since it is larger than the sum of its proper divisors (29573913483).

61564646517 is a wasteful number, since it uses less digits than its factorization.

61564646517 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 118961.

The product of its digits is 3628800, while the sum is 51.

Subtracting 61564646517 from its reverse (71564646516), we obtain a palindrome (9999999999).

The spelling of 61564646517 in words is "sixty-one billion, five hundred sixty-four million, six hundred forty-six thousand, five hundred seventeen".