77566901 has 4 divisors (see below), whose sum is σ = 78177792. Its totient is φ = 76956012.

The previous prime is 77566891. The next prime is 77566913. The reversal of 77566901 is 10966577.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 10966577 = 127 ⋅86351.

It is a cyclic number.

It is not a de Polignac number, because 77566901 - 2¹⁸ = 77304757 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 (77566201) 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, 305255 + ... + 305508.

It is an arithmetic number, because the mean of its divisors is an integer number (19544448).

Almost surely, 2^77566901 is an apocalyptic number.

It is an amenable number.

77566901 is a deficient number, since it is larger than the sum of its proper divisors (610891).

77566901 is a wasteful number, since it uses less digits than its factorization.

77566901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 610890.

The product of its (nonzero) digits is 79380, while the sum is 41.

The square root of 77566901 is about 8807.2073326339. The cubic root of 77566901 is about 426.4735947611.

It can be divided in two parts, 775 and 66901, that added together give a palindrome (67676).

The spelling of 77566901 in words is "seventy-seven million, five hundred sixty-six thousand, nine hundred one".