61164944640 has 288 divisors, whose sum is σ = 229820492160. Its totient is φ = 15351054336.

The previous prime is 61164944587. The next prime is 61164944653. The reversal of 61164944640 is 4644946116.

61164944640 is a `hidden beast` number, since 6 + 1 + 164 + 9 + 446 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 535467 + ... + 639573.

It is an arithmetic number, because the mean of its divisors is an integer number (797987820).

Almost surely, 2^61164944640 is an apocalyptic number.

61164944640 is a gapful number since it is divisible by the number (60) 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 61164944640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (114910246080).

61164944640 is an abundant number, since it is smaller than the sum of its proper divisors (168655547520).

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

61164944640 is a wasteful number, since it uses less digits than its factorization.

61164944640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104154 (or 104134 counting only the distinct ones).

The product of its (nonzero) digits is 497664, while the sum is 45.

The spelling of 61164944640 in words is "sixty-one billion, one hundred sixty-four million, nine hundred forty-four thousand, six hundred forty".