81937886 has 8 divisors (see below), whose sum is σ = 122985480. Its totient is φ = 40942728.

The previous prime is 81937883. The next prime is 81937897. The reversal of 81937886 is 68873918.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81937883) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8936 + ... + 15611.

It is an arithmetic number, because the mean of its divisors is an integer number (15373185).

Almost surely, 2^81937886 is an apocalyptic number.

81937886 is a deficient number, since it is larger than the sum of its proper divisors (41047594).

81937886 is a wasteful number, since it uses less digits than its factorization.

81937886 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26218.

The product of its digits is 580608, while the sum is 50.

The square root of 81937886 is about 9051.9548165023. The cubic root of 81937886 is about 434.3384244758.

The spelling of 81937886 in words is "eighty-one million, nine hundred thirty-seven thousand, eight hundred eighty-six".