77255172 has 18 divisors (see below), whose sum is σ = 195283998. Its totient is φ = 25751712.

The previous prime is 77255141. The next prime is 77255173. The reversal of 77255172 is 27155277.

It can be written as a sum of positive squares in only one way, i.e., 72692676 + 4562496 = 8526^2 + 2136^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a Harshad number since it is a multiple of its sum of digits (36), and also a Moran number because the ratio is a prime number: 2145977 = 77255172 / (7 + 7 + 2 + 5 + 5 + 1 + 7 + 2).

It is not an unprimeable number, because it can be changed into a prime (77255173) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1072953 + ... + 1073024.

It is an arithmetic number, because the mean of its divisors is an integer number (10849111).

Almost surely, 2^77255172 is an apocalyptic number.

It is an amenable number.

77255172 is an abundant number, since it is smaller than the sum of its proper divisors (118028826).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

77255172 is a wasteful number, since it uses less digits than its factorization.

77255172 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2145987 (or 2145982 counting only the distinct ones).

The product of its digits is 34300, while the sum is 36.

The square root of 77255172 is about 8789.4921354991. The cubic root of 77255172 is about 425.9015179344.

The spelling of 77255172 in words is "seventy-seven million, two hundred fifty-five thousand, one hundred seventy-two".