61815978074 has 8 divisors (see below), whose sum is σ = 92999113428. Its totient is φ = 30816273600.

The previous prime is 61815978073. The next prime is 61815978167. The reversal of 61815978074 is 47087951816.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 59241126025 + 2574852049 = 243395^2 + 50743^2 .

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 (61815978073) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45856877 + ... + 45858224.

Almost surely, 2^61815978074 is an apocalyptic number.

61815978074 is a deficient number, since it is larger than the sum of its proper divisors (31183135354).

61815978074 is a wasteful number, since it uses less digits than its factorization.

61815978074 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91715440.

The product of its (nonzero) digits is 3386880, while the sum is 56.

The spelling of 61815978074 in words is "sixty-one billion, eight hundred fifteen million, nine hundred seventy-eight thousand, seventy-four".