61665155616 has 48 divisors (see below), whose sum is σ = 162016231104. Its totient is φ = 20536614144.

The previous prime is 61665155603. The next prime is 61665155621. The reversal of 61665155616 is 61655156616.

It is a tau number, because it is divible by the number of its divisors (48).

It is a Harshad number since it is a multiple of its sum of digits (48).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 180300 + ... + 394763.

It is an arithmetic number, because the mean of its divisors is an integer number (3375338148).

Almost surely, 2^61665155616 is an apocalyptic number.

It is an amenable number.

61665155616 is an abundant number, since it is smaller than the sum of its proper divisors (100351075488).

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

61665155616 is a wasteful number, since it uses less digits than its factorization.

61665155616 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 576193 (or 576185 counting only the distinct ones).

The product of its digits is 972000, while the sum is 48.

The spelling of 61665155616 in words is "sixty-one billion, six hundred sixty-five million, one hundred fifty-five thousand, six hundred sixteen".