77391864 has 192 divisors, whose sum is σ = 248976000. Its totient is φ = 21461760.

The previous prime is 77391857. The next prime is 77391869. The reversal of 77391864 is 46819377.

It is a super-2 number, since 2×77391864² = 11979001226788992, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77391869) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 556707 + ... + 556845.

It is an arithmetic number, because the mean of its divisors is an integer number (1296750).

Almost surely, 2^77391864 is an apocalyptic number.

77391864 is a gapful number since it is divisible by the number (74) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 77391864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (124488000).

77391864 is an abundant number, since it is smaller than the sum of its proper divisors (171584136).

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

77391864 is a wasteful number, since it uses less digits than its factorization.

77391864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 218 (or 211 counting only the distinct ones).

The product of its digits is 254016, while the sum is 45.

The square root of 77391864 is about 8797.2645748551. The cubic root of 77391864 is about 426.1525605798.

The spelling of 77391864 in words is "seventy-seven million, three hundred ninety-one thousand, eight hundred sixty-four".