61331100091 has 4 divisors (see below), whose sum is σ = 61332073432. Its totient is φ = 61330126752.

The previous prime is 61331100023. The next prime is 61331100097. The reversal of 61331100091 is 19000113316.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 61331100091 - 2⁹ = 61331099579 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61331100097) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 385086 + ... + 520531.

It is an arithmetic number, because the mean of its divisors is an integer number (15333018358).

Almost surely, 2^61331100091 is an apocalyptic number.

61331100091 is a deficient number, since it is larger than the sum of its proper divisors (973341).

61331100091 is an equidigital number, since it uses as much as digits as its factorization.

61331100091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 973340.

The product of its (nonzero) digits is 486, while the sum is 25.

The spelling of 61331100091 in words is "sixty-one billion, three hundred thirty-one million, one hundred thousand, ninety-one".