77661253 has 4 divisors (see below), whose sum is σ = 82229580. Its totient is φ = 73092928.

The previous prime is 77661251. The next prime is 77661277. The reversal of 77661253 is 35216677.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 45603009 + 32058244 = 6753^2 + 5662^2 .

It is not a de Polignac number, because 77661253 - 2¹ = 77661251 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 (77661251) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2284138 + ... + 2284171.

It is an arithmetic number, because the mean of its divisors is an integer number (20557395).

Almost surely, 2^77661253 is an apocalyptic number.

It is an amenable number.

77661253 is a deficient number, since it is larger than the sum of its proper divisors (4568327).

77661253 is a wasteful number, since it uses less digits than its factorization.

77661253 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4568326.

The product of its digits is 52920, while the sum is 37.

The square root of 77661253 is about 8812.5622267307. The cubic root of 77661253 is about 426.6464448288.

The spelling of 77661253 in words is "seventy-seven million, six hundred sixty-one thousand, two hundred fifty-three".