61656500978 has 8 divisors (see below), whose sum is σ = 92531490480. Its totient is φ = 30812670820.

The previous prime is 61656500909. The next prime is 61656500987. The reversal of 61656500978 is 87900565616.

61656500978 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 a super-2 number, since 2×61656500978² (a number of 22 digits) contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7784888 + ... + 7792803.

It is an arithmetic number, because the mean of its divisors is an integer number (11566436310).

Almost surely, 2^61656500978 is an apocalyptic number.

61656500978 is a deficient number, since it is larger than the sum of its proper divisors (30874989502).

61656500978 is a wasteful number, since it uses less digits than its factorization.

61656500978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15579672.

The product of its (nonzero) digits is 2721600, while the sum is 53.

The spelling of 61656500978 in words is "sixty-one billion, six hundred fifty-six million, five hundred thousand, nine hundred seventy-eight".