77965009920 has 1408 divisors, whose sum is σ = 344100372480. Its totient is φ = 16349921280.

The previous prime is 77965009907. The next prime is 77965009931. The reversal of 77965009920 is 2990056977.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 689955784 + ... + 689955896.

Almost surely, 2^77965009920 is an apocalyptic number.

77965009920 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 77965009920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (172050186240).

77965009920 is an abundant number, since it is smaller than the sum of its proper divisors (266135362560).

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

77965009920 is a wasteful number, since it uses less digits than its factorization.

77965009920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 208 (or 184 counting only the distinct ones).

The product of its (nonzero) digits is 2143260, while the sum is 54.

The spelling of 77965009920 in words is "seventy-seven billion, nine hundred sixty-five million, nine thousand, nine hundred twenty".