77939121 has 32 divisors (see below), whose sum is σ = 119024640. Its totient is φ = 44967744.

The previous prime is 77939119. The next prime is 77939123. The reversal of 77939121 is 12193977.

It is an interprime number because it is at equal distance from previous prime (77939119) and next prime (77939123).

It is not a de Polignac number, because 77939121 - 2¹ = 77939119 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a self number, because there is not a number n which added to its sum of digits gives 77939121.

It is not an unprimeable number, because it can be changed into a prime (77939123) 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 in 31 ways as a sum of consecutive naturals, for example, 78796 + ... + 79778.

It is an arithmetic number, because the mean of its divisors is an integer number (3719520).

Almost surely, 2^77939121 is an apocalyptic number.

It is an amenable number.

77939121 is a deficient number, since it is larger than the sum of its proper divisors (41085519).

77939121 is a wasteful number, since it uses less digits than its factorization.

77939121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1125.

The product of its digits is 23814, while the sum is 39.

The square root of 77939121 is about 8828.3135988704. The cubic root of 77939121 is about 427.1546789003.

The spelling of 77939121 in words is "seventy-seven million, nine hundred thirty-nine thousand, one hundred twenty-one".