77999121 has 12 divisors (see below), whose sum is σ = 114575760. Its totient is φ = 51117720.

The previous prime is 77999087. The next prime is 77999143. The reversal of 77999121 is 12199977.

It is not a de Polignac number, because 77999121 - 2¹³ = 77990929 is a prime.

It is not an unprimeable number, because it can be changed into a prime (77999191) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 72915 + ... + 73976.

It is an arithmetic number, because the mean of its divisors is an integer number (9547980).

Almost surely, 2^77999121 is an apocalyptic number.

It is an amenable number.

77999121 is a deficient number, since it is larger than the sum of its proper divisors (36576639).

77999121 is a wasteful number, since it uses less digits than its factorization.

77999121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146956 (or 146953 counting only the distinct ones).

The product of its digits is 71442, while the sum is 45.

The square root of 77999121 is about 8831.7111026120. The cubic root of 77999121 is about 427.2642631779.

The spelling of 77999121 in words is "seventy-seven million, nine hundred ninety-nine thousand, one hundred twenty-one".