77957897784 has 96 divisors (see below), whose sum is σ = 213931640880. Its totient is φ = 23658365952.

The previous prime is 77957897779. The next prime is 77957897789. The reversal of 77957897784 is 48779875977.

It is an interprime number because it is at equal distance from previous prime (77957897779) and next prime (77957897789).

It is a super-2 number, since 2×77957897784² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (78).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77957897789) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 164442 + ... + 427734.

Almost surely, 2^77957897784 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 77957897784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (106965820440).

77957897784 is an abundant number, since it is smaller than the sum of its proper divisors (135973743096).

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

77957897784 is a wasteful number, since it uses less digits than its factorization.

77957897784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 263401 (or 263384 counting only the distinct ones).

The product of its digits is 1742549760, while the sum is 78.

The spelling of 77957897784 in words is "seventy-seven billion, nine hundred fifty-seven million, eight hundred ninety-seven thousand, seven hundred eighty-four".