61644904977 has 16 divisors (see below), whose sum is σ = 91608528960. Its totient is φ = 36643410432.

The previous prime is 61644904973. The next prime is 61644905057. The reversal of 61644904977 is 77940944616.

It is not a de Polignac number, because 61644904977 - 2² = 61644904973 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (57).

It is not an unprimeable number, because it can be changed into a prime (61644904973) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 31807548 + ... + 31809485.

It is an arithmetic number, because the mean of its divisors is an integer number (5725533060).

Almost surely, 2^61644904977 is an apocalyptic number.

It is an amenable number.

61644904977 is a deficient number, since it is larger than the sum of its proper divisors (29963623983).

61644904977 is a wasteful number, since it uses less digits than its factorization.

61644904977 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63617072.

The product of its (nonzero) digits is 9144576, while the sum is 57.

The spelling of 61644904977 in words is "sixty-one billion, six hundred forty-four million, nine hundred four thousand, nine hundred seventy-seven".