651236610561 has 4 divisors (see below), whose sum is σ = 868315480752. Its totient is φ = 434157740372.

The previous prime is 651236610551. The next prime is 651236610593. The reversal of 651236610561 is 165016632156.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 651236610561 - 2²¹ = 651234513409 is a prime.

It is not an unprimeable number, because it can be changed into a prime (651236610551) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 108539435091 + ... + 108539435096.

It is an arithmetic number, because the mean of its divisors is an integer number (217078870188).

Almost surely, 2^651236610561 is an apocalyptic number.

It is an amenable number.

651236610561 is a deficient number, since it is larger than the sum of its proper divisors (217078870191).

651236610561 is a wasteful number, since it uses less digits than its factorization.

651236610561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 217078870190.

The product of its (nonzero) digits is 194400, while the sum is 42.

The spelling of 651236610561 in words is "six hundred fifty-one billion, two hundred thirty-six million, six hundred ten thousand, five hundred sixty-one".