77961582 has 64 divisors (see below), whose sum is σ = 185310720. Its totient is φ = 24235200.

The previous prime is 77961581. The next prime is 77961601. The reversal of 77961582 is 28516977.

77961582 is a `hidden beast` number, since 7 + 7 + 9 + 61 + 582 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77961581) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 50157 + ... + 51687.

It is an arithmetic number, because the mean of its divisors is an integer number (2895480).

Almost surely, 2^77961582 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 77961582, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (92655360).

77961582 is an abundant number, since it is smaller than the sum of its proper divisors (107349138).

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

77961582 is a wasteful number, since it uses less digits than its factorization.

77961582 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1606 (or 1600 counting only the distinct ones).

The product of its digits is 211680, while the sum is 45.

The square root of 77961582 is about 8829.5856074903. The cubic root of 77961582 is about 427.1957083586.

The spelling of 77961582 in words is "seventy-seven million, nine hundred sixty-one thousand, five hundred eighty-two".