81878744825 has 12 divisors (see below), whose sum is σ = 101552430288. Its totient is φ = 65488294800.

The previous prime is 81878744809. The next prime is 81878744861. The reversal of 81878744825 is 52844787818.

It is not a de Polignac number, because 81878744825 - 2⁴ = 81878744809 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 253211 + ... + 477360.

It is an arithmetic number, because the mean of its divisors is an integer number (8462702524).

Almost surely, 2^81878744825 is an apocalyptic number.

It is an amenable number.

81878744825 is a deficient number, since it is larger than the sum of its proper divisors (19673685463).

81878744825 is a wasteful number, since it uses less digits than its factorization.

81878744825 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 735064 (or 735059 counting only the distinct ones).

The product of its digits is 32112640, while the sum is 62.

The spelling of 81878744825 in words is "eighty-one billion, eight hundred seventy-eight million, seven hundred forty-four thousand, eight hundred twenty-five".