61864459521 has 8 divisors (see below), whose sum is σ = 82487527200. Its totient is φ = 41242182432.

The previous prime is 61864459471. The next prime is 61864459561. The reversal of 61864459521 is 12595446816.

61864459521 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 61864459521 - 2²⁵ = 61830905089 is a prime.

It is a super-2 number, since 2×61864459521² (a number of 22 digits) contains 22 as substring.

It is a Smith number, since the sum of its digits (51) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (61864459561) 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, 18805 + ... + 352253.

It is an arithmetic number, because the mean of its divisors is an integer number (10310940900).

Almost surely, 2^61864459521 is an apocalyptic number.

It is an amenable number.

61864459521 is a deficient number, since it is larger than the sum of its proper divisors (20623067679).

61864459521 is a wasteful number, since it uses less digits than its factorization.

61864459521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 395295.

The product of its digits is 2073600, while the sum is 51.

The spelling of 61864459521 in words is "sixty-one billion, eight hundred sixty-four million, four hundred fifty-nine thousand, five hundred twenty-one".