77661252 has 18 divisors (see below), whose sum is σ = 196310478. Its totient is φ = 25887072.

The previous prime is 77661251. The next prime is 77661277. The reversal of 77661252 is 25216677.

It can be written as a sum of positive squares in only one way, i.e., 46457856 + 31203396 = 6816^2 + 5586^2 .

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

It is a super-3 number, since 3×77661252³ (a number of 25 digits) contains 333 as substring.

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: 2157257 = 77661252 / (7 + 7 + 6 + 6 + 1 + 2 + 5 + 2).

It is not an unprimeable number, because it can be changed into a prime (77661251) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1078593 + ... + 1078664.

Almost surely, 2^77661252 is an apocalyptic number.

It is an amenable number.

77661252 is an abundant number, since it is smaller than the sum of its proper divisors (118649226).

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

77661252 is a wasteful number, since it uses less digits than its factorization.

77661252 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2157267 (or 2157262 counting only the distinct ones).

The product of its digits is 35280, while the sum is 36.

The square root of 77661252 is about 8812.5621699935. The cubic root of 77661252 is about 426.6464429976.

The spelling of 77661252 in words is "seventy-seven million, six hundred sixty-one thousand, two hundred fifty-two".