77961530 has 8 divisors (see below), whose sum is σ = 140330772. Its totient is φ = 31184608.

The previous prime is 77961523. The next prime is 77961539. The reversal of 77961530 is 3516977.

It can be written as a sum of positive squares in 2 ways, for example, as 75359761 + 2601769 = 8681^2 + 1613^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (77961539) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3898067 + ... + 3898086.

Almost surely, 2^77961530 is an apocalyptic number.

77961530 is a deficient number, since it is larger than the sum of its proper divisors (62369242).

77961530 is a wasteful number, since it uses less digits than its factorization.

77961530 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7796160.

The product of its (nonzero) digits is 39690, while the sum is 38.

The square root of 77961530 is about 8829.5826628443. The cubic root of 77961530 is about 427.1956133794.

The spelling of 77961530 in words is "seventy-seven million, nine hundred sixty-one thousand, five hundred thirty".