61918100064 has 72 divisors (see below), whose sum is σ = 176124482352. Its totient is φ = 20634105600.

The previous prime is 61918100063. The next prime is 61918100099. The reversal of 61918100064 is 46000181916.

It is a happy number.

61918100064 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (72).

It is a super-2 number, since 2×61918100064² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61918100063) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1199589 + ... + 1250139.

It is an arithmetic number, because the mean of its divisors is an integer number (2446173366).

Almost surely, 2^61918100064 is an apocalyptic number.

It is an amenable number.

61918100064 is an abundant number, since it is smaller than the sum of its proper divisors (114206382288).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

61918100064 is a wasteful number, since it uses less digits than its factorization.

61918100064 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 54820 (or 54809 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 36.

The spelling of 61918100064 in words is "sixty-one billion, nine hundred eighteen million, one hundred thousand, sixty-four".