61807520818 has 4 divisors (see below), whose sum is σ = 92711281230. Its totient is φ = 30903760408.

The previous prime is 61807520813. The next prime is 61807520821. The reversal of 61807520818 is 81802570816.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 42342527529 + 19464993289 = 205773^2 + 139517^2 .

It is not an unprimeable number, because it can be changed into a prime (61807520813) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15451880203 + ... + 15451880206.

Almost surely, 2^61807520818 is an apocalyptic number.

61807520818 is a deficient number, since it is larger than the sum of its proper divisors (30903760412).

61807520818 is a wasteful number, since it uses less digits than its factorization.

61807520818 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30903760411.

The product of its (nonzero) digits is 215040, while the sum is 46.

The spelling of 61807520818 in words is "sixty-one billion, eight hundred seven million, five hundred twenty thousand, eight hundred eighteen".