61855933955817 has 4 divisors (see below), whose sum is σ = 82474578607760. Its totient is φ = 41237289303876.

The previous prime is 61855933955801. The next prime is 61855933955839. The reversal of 61855933955817 is 71855933955816.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 61855933955817 - 2⁴ = 61855933955801 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61855933955617) 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, 10309322325967 + ... + 10309322325972.

It is an arithmetic number, because the mean of its divisors is an integer number (20618644651940).

Almost surely, 2^{61855933955817} is an apocalyptic number.

It is an amenable number.

61855933955817 is a deficient number, since it is larger than the sum of its proper divisors (20618644651943).

61855933955817 is a wasteful number, since it uses less digits than its factorization.

61855933955817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20618644651942.

The product of its digits is 1224720000, while the sum is 75.

Subtracting 61855933955817 from its reverse (71855933955816), we obtain a palindrome (9999999999999).

The spelling of 61855933955817 in words is "sixty-one trillion, eight hundred fifty-five billion, nine hundred thirty-three million, nine hundred fifty-five thousand, eight hundred seventeen".