77861457 has 12 divisors (see below), whose sum is σ = 112566324. Its totient is φ = 51861600.

The previous prime is 77861453. The next prime is 77861467. The reversal of 77861457 is 75416877.

It can be written as a sum of positive squares in 2 ways, for example, as 66732561 + 11128896 = 8169^2 + 3336^2 .

It is not a de Polignac number, because 77861457 - 2² = 77861453 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77861453) 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, 9207 + ... + 15507.

It is an arithmetic number, because the mean of its divisors is an integer number (9380527).

Almost surely, 2^77861457 is an apocalyptic number.

It is an amenable number.

77861457 is a deficient number, since it is larger than the sum of its proper divisors (34704867).

77861457 is a wasteful number, since it uses less digits than its factorization.

77861457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7680 (or 7677 counting only the distinct ones).

The product of its digits is 329280, while the sum is 45.

The square root of 77861457 is about 8823.9139275041. The cubic root of 77861457 is about 427.0127494653.

The spelling of 77861457 in words is "seventy-seven million, eight hundred sixty-one thousand, four hundred fifty-seven".