61531788386 has 4 divisors (see below), whose sum is σ = 92297682582. Its totient is φ = 30765894192.

The previous prime is 61531788343. The next prime is 61531788497. The reversal of 61531788386 is 68388713516.

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., 58789276225 + 2742512161 = 242465^2 + 52369^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 15382947095 + ... + 15382947098.

Almost surely, 2^61531788386 is an apocalyptic number.

61531788386 is a deficient number, since it is larger than the sum of its proper divisors (30765894196).

61531788386 is a wasteful number, since it uses less digits than its factorization.

61531788386 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30765894195.

The product of its digits is 5806080, while the sum is 56.

The spelling of 61531788386 in words is "sixty-one billion, five hundred thirty-one million, seven hundred eighty-eight thousand, three hundred eighty-six".