61331100800991 has 64 divisors (see below), whose sum is σ = 100325816487936. Its totient is φ = 32527791820800.

The previous prime is 61331100800987. The next prime is 61331100801001. The reversal of 61331100800991 is 19900800113316.

It is not a de Polignac number, because 61331100800991 - 2² = 61331100800987 is a prime.

It is a super-2 number, since 2×61331100800991² (a number of 28 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61331100800951) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 167154426 + ... + 167520936.

It is an arithmetic number, because the mean of its divisors is an integer number (1567590882624).

Almost surely, 2^{61331100800991} is an apocalyptic number.

61331100800991 is a deficient number, since it is larger than the sum of its proper divisors (38994715686945).

61331100800991 is a wasteful number, since it uses less digits than its factorization.

61331100800991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 373032.

The product of its (nonzero) digits is 34992, while the sum is 42.

The spelling of 61331100800991 in words is "sixty-one trillion, three hundred thirty-one billion, one hundred million, eight hundred thousand, nine hundred ninety-one".