77920901 has 6 divisors (see below), whose sum is σ = 78283206. Its totient is φ = 77560200.

The previous prime is 77920897. The next prime is 77920903. The reversal of 77920901 is 10902977.

It can be written as a sum of positive squares in only one way, i.e., 70576801 + 7344100 = 8401^2 + 2710^2 .

It is not a de Polignac number, because 77920901 - 2² = 77920897 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77920903) 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 5 ways as a sum of consecutive naturals, for example, 72911 + ... + 73971.

It is an arithmetic number, because the mean of its divisors is an integer number (13047201).

Almost surely, 2^77920901 is an apocalyptic number.

It is an amenable number.

77920901 is a deficient number, since it is larger than the sum of its proper divisors (362305).

77920901 is an equidigital number, since it uses as much as digits as its factorization.

77920901 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1603 (or 1332 counting only the distinct ones).

The product of its (nonzero) digits is 7938, while the sum is 35.

The square root of 77920901 is about 8827.2816313971. The cubic root of 77920901 is about 427.1213906762.

The spelling of 77920901 in words is "seventy-seven million, nine hundred twenty thousand, nine hundred one".