81487637 has 48 divisors (see below), whose sum is σ = 111355200. Its totient is φ = 58786560.

The previous prime is 81487621. The next prime is 81487639. The reversal of 81487637 is 73678418.

It is not a de Polignac number, because 81487637 - 2⁴ = 81487621 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81487639) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 747539 + ... + 747647.

It is an arithmetic number, because the mean of its divisors is an integer number (2319900).

Almost surely, 2^81487637 is an apocalyptic number.

It is an amenable number.

81487637 is a deficient number, since it is larger than the sum of its proper divisors (29867563).

81487637 is a wasteful number, since it uses less digits than its factorization.

81487637 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 226 (or 219 counting only the distinct ones).

The product of its digits is 225792, while the sum is 44.

The square root of 81487637 is about 9027.0502934236. The cubic root of 81487637 is about 433.5413990290.

The spelling of 81487637 in words is "eighty-one million, four hundred eighty-seven thousand, six hundred thirty-seven".