77442639 has 8 divisors (see below), whose sum is σ = 103712640. Its totient is φ = 51400536.

The previous prime is 77442637. The next prime is 77442649. The reversal of 77442639 is 93624477.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 77442639 - 2¹ = 77442637 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 77442639.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77442637) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 56179 + ... + 57540.

It is an arithmetic number, because the mean of its divisors is an integer number (12964080).

Almost surely, 2^77442639 is an apocalyptic number.

77442639 is a deficient number, since it is larger than the sum of its proper divisors (26270001).

77442639 is a wasteful number, since it uses less digits than its factorization.

77442639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 113949.

The product of its digits is 254016, while the sum is 42.

The square root of 77442639 is about 8800.1499419044. The cubic root of 77442639 is about 426.2457364635.

The spelling of 77442639 in words is "seventy-seven million, four hundred forty-two thousand, six hundred thirty-nine".