64672129561 has 8 divisors (see below), whose sum is σ = 69783746760. Its totient is φ = 59580060672.

The previous prime is 64672129513. The next prime is 64672129591. The reversal of 64672129561 is 16592127646.

It can be written as a sum of positive squares in 4 ways, for example, as 16353936 + 64655775625 = 4044^2 + 254275^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-64672129561 is a prime.

It is a super-4 number, since 4×64672129561⁴ (a number of 44 digits) contains 4444 as substring.

It is not an unprimeable number, because it can be changed into a prime (64672129591) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4880200 + ... + 4893433.

It is an arithmetic number, because the mean of its divisors is an integer number (8722968345).

Almost surely, 2^64672129561 is an apocalyptic number.

It is an amenable number.

64672129561 is a deficient number, since it is larger than the sum of its proper divisors (5111617199).

64672129561 is a wasteful number, since it uses less digits than its factorization.

64672129561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9774155.

The product of its digits is 1088640, while the sum is 49.

The spelling of 64672129561 in words is "sixty-four billion, six hundred seventy-two million, one hundred twenty-nine thousand, five hundred sixty-one".