61581545779715 has 32 divisors (see below), whose sum is σ = 86981798647296. Its totient is φ = 41419904071680.

The previous prime is 61581545779673. The next prime is 61581545779769. The reversal of 61581545779715 is 51797754518516.

It is not a de Polignac number, because 61581545779715 - 2⁶ = 61581545779651 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 898835192 + ... + 898903701.

It is an arithmetic number, because the mean of its divisors is an integer number (2718181207728).

Almost surely, 2^{61581545779715} is an apocalyptic number.

61581545779715 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

61581545779715 is a deficient number, since it is larger than the sum of its proper divisors (25400252867581).

61581545779715 is a wasteful number, since it uses less digits than its factorization.

61581545779715 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1797738959.

The product of its digits is 370440000, while the sum is 71.

The spelling of 61581545779715 in words is "sixty-one trillion, five hundred eighty-one billion, five hundred forty-five million, seven hundred seventy-nine thousand, seven hundred fifteen".