77491972 has 12 divisors (see below), whose sum is σ = 135997596. Its totient is φ = 38635520.

The previous prime is 77491963. The next prime is 77491979. The reversal of 77491972 is 27919477.

It can be written as a sum of positive squares in 2 ways, for example, as 15492096 + 61999876 = 3936^2 + 7874^2 .

It is not an unprimeable number, because it can be changed into a prime (77491979) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26029 + ... + 28852.

It is an arithmetic number, because the mean of its divisors is an integer number (11333133).

Almost surely, 2^77491972 is an apocalyptic number.

It is an amenable number.

77491972 is a deficient number, since it is larger than the sum of its proper divisors (58505624).

77491972 is a wasteful number, since it uses less digits than its factorization.

77491972 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55238 (or 55236 counting only the distinct ones).

The product of its digits is 222264, while the sum is 46.

The square root of 77491972 is about 8802.9524592605. The cubic root of 77491972 is about 426.3362271701.

The spelling of 77491972 in words is "seventy-seven million, four hundred ninety-one thousand, nine hundred seventy-two".