61939520581 has 8 divisors (see below), whose sum is σ = 65424491264. Its totient is φ = 58547482560.

The previous prime is 61939520563. The next prime is 61939520641. The reversal of 61939520581 is 18502593916.

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

It is a cyclic number.

It is not a de Polignac number, because 61939520581 - 2⁵ = 61939520549 is a prime.

It is a super-2 number, since 2×61939520581² (a number of 22 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61939529581) 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 7 ways as a sum of consecutive naturals, for example, 23231796 + ... + 23234461.

It is an arithmetic number, because the mean of its divisors is an integer number (8178061408).

Almost surely, 2^61939520581 is an apocalyptic number.

It is an amenable number.

61939520581 is a deficient number, since it is larger than the sum of its proper divisors (3484970683).

61939520581 is a wasteful number, since it uses less digits than its factorization.

61939520581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46466331.

The product of its (nonzero) digits is 583200, while the sum is 49.

The spelling of 61939520581 in words is "sixty-one billion, nine hundred thirty-nine million, five hundred twenty thousand, five hundred eighty-one".