77906888640 has 1232 divisors, whose sum is σ = 345562245120. Its totient is φ = 16325867520.

The previous prime is 77906888629. The next prime is 77906888651. The reversal of 77906888640 is 4688860977.

It is an interprime number because it is at equal distance from previous prime (77906888629) and next prime (77906888651).

It is a super-2 number, since 2×77906888640² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 175 ways as a sum of consecutive naturals, for example, 2513125425 + ... + 2513125455.

Almost surely, 2^77906888640 is an apocalyptic number.

77906888640 is a gapful number since it is divisible by the number (70) 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 77906888640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (172781122560).

77906888640 is an abundant number, since it is smaller than the sum of its proper divisors (267655356480).

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

77906888640 is an equidigital number, since it uses as much as digits as its factorization.

77906888640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 104 (or 67 counting only the distinct ones).

The product of its (nonzero) digits is 32514048, while the sum is 63.

The spelling of 77906888640 in words is "seventy-seven billion, nine hundred six million, eight hundred eighty-eight thousand, six hundred forty".