77621869 has 6 divisors (see below), whose sum is σ = 84052266. Its totient is φ = 71650800.

The previous prime is 77621857. The next prime is 77621879. The reversal of 77621869 is 96812677.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 1408969 + 76212900 = 1187^2 + 8730^2 .

It is not a de Polignac number, because 77621869 - 2¹⁵ = 77589101 is a prime.

It is a super-2 number, since 2×77621869² = 12050309094106322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77621879) 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, 229482 + ... + 229819.

It is an arithmetic number, because the mean of its divisors is an integer number (14008711).

Almost surely, 2^77621869 is an apocalyptic number.

It is an amenable number.

77621869 is a deficient number, since it is larger than the sum of its proper divisors (6430397).

77621869 is a wasteful number, since it uses less digits than its factorization.

77621869 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 459327 (or 459314 counting only the distinct ones).

The product of its digits is 254016, while the sum is 46.

The square root of 77621869 is about 8810.3274059481. The cubic root of 77621869 is about 426.5743115399.

The spelling of 77621869 in words is "seventy-seven million, six hundred twenty-one thousand, eight hundred sixty-nine".