61660678464 has 1008 divisors, whose sum is σ = 239243583488. Its totient is φ = 15396480000.

The previous prime is 61660678459. The next prime is 61660678477. The reversal of 61660678464 is 46487606616.

It is a happy number.

61660678464 is a `hidden beast` number, since 61 + 6 + 60 + 67 + 8 + 464 = 666.

It is a tau number, because it is divible by the number of its divisors (1008).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a self number, because there is not a number n which added to its sum of digits gives 61660678464.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 408348789 + ... + 408348939.

Almost surely, 2^61660678464 is an apocalyptic number.

61660678464 is a gapful number since it is divisible by the number (64) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 61660678464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (119621791744).

61660678464 is an abundant number, since it is smaller than the sum of its proper divisors (177582905024).

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

61660678464 is a wasteful number, since it uses less digits than its factorization.

61660678464 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 238 (or 205 counting only the distinct ones).

The product of its (nonzero) digits is 6967296, while the sum is 54.

The spelling of 61660678464 in words is "sixty-one billion, six hundred sixty million, six hundred seventy-eight thousand, four hundred sixty-four".