61581330393975 has 108 divisors (see below), whose sum is σ = 128327806662120. Its totient is φ = 28146901507200.

The previous prime is 61581330393953. The next prime is 61581330393991. The reversal of 61581330393975 is 57939303318516.

61581330393975 is a `hidden beast` number, since 6 + 158 + 1 + 3 + 3 + 0 + 393 + 97 + 5 = 666.

It is not a de Polignac number, because 61581330393975 - 2¹⁸ = 61581330131831 is a prime.

It is a hoax number, since the sum of its digits (63) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 68026621 + ... + 68925929.

Almost surely, 2^{61581330393975} is an apocalyptic number.

61581330393975 is an abundant number, since it is smaller than the sum of its proper divisors (66746476268145).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

61581330393975 is a wasteful number, since it uses less digits than its factorization.

61581330393975 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 905550 (or 905535 counting only the distinct ones).

The product of its (nonzero) digits is 55112400, while the sum is 63.

The spelling of 61581330393975 in words is "sixty-one trillion, five hundred eighty-one billion, three hundred thirty million, three hundred ninety-three thousand, nine hundred seventy-five".