77661902 has 4 divisors (see below), whose sum is σ = 116492856. Its totient is φ = 38830950.

The previous prime is 77661901. The next prime is 77661919. The reversal of 77661902 is 20916677.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 20916677 = 1423 ⋅14699.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77661901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19415474 + ... + 19415477.

It is an arithmetic number, because the mean of its divisors is an integer number (29123214).

Almost surely, 2^77661902 is an apocalyptic number.

77661902 is a deficient number, since it is larger than the sum of its proper divisors (38830954).

77661902 is a wasteful number, since it uses less digits than its factorization.

77661902 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38830953.

The product of its (nonzero) digits is 31752, while the sum is 38.

The square root of 77661902 is about 8812.5990490888. The cubic root of 77661902 is about 426.6476332927.

The spelling of 77661902 in words is "seventy-seven million, six hundred sixty-one thousand, nine hundred two".