77611520 has 160 divisors (see below), whose sum is σ = 219200256. Its totient is φ = 25804800.

The previous prime is 77611493. The next prime is 77611529. The reversal of 77611520 is 2511677.

It is a tau number, because it is divible by the number of its divisors (160).

It is a hoax number, since the sum of its digits (29) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (77611529) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1093085 + ... + 1093155.

Almost surely, 2^77611520 is an apocalyptic number.

77611520 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 77611520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (109600128).

77611520 is an abundant number, since it is smaller than the sum of its proper divisors (141588736).

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

77611520 is an equidigital number, since it uses as much as digits as its factorization.

77611520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 162 (or 146 counting only the distinct ones).

The product of its (nonzero) digits is 2940, while the sum is 29.

The square root of 77611520 is about 8809.7400642698. The cubic root of 77611520 is about 426.5553529061. Note that the first 3 decimals are identical.

The spelling of 77611520 in words is "seventy-seven million, six hundred eleven thousand, five hundred twenty".