81925278 has 16 divisors (see below), whose sum is σ = 173489040. Its totient is φ = 25702016.

The previous prime is 81925247. The next prime is 81925279. The reversal of 81925278 is 87252918.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81925279) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 401493 + ... + 401696.

It is an arithmetic number, because the mean of its divisors is an integer number (10843065).

Almost surely, 2^81925278 is an apocalyptic number.

81925278 is an abundant number, since it is smaller than the sum of its proper divisors (91563762).

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

81925278 is a wasteful number, since it uses less digits than its factorization.

81925278 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 803211.

The product of its digits is 80640, while the sum is 42.

The square root of 81925278 is about 9051.2583655534. The cubic root of 81925278 is about 434.3161457310.

The spelling of 81925278 in words is "eighty-one million, nine hundred twenty-five thousand, two hundred seventy-eight".