81489992631 has 8 divisors (see below), whose sum is σ = 109708210560. Its totient is φ = 53799218232.

The previous prime is 81489992603. The next prime is 81489992641. The reversal of 81489992631 is 13629998418.

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

It is not a de Polignac number, because 81489992631 - 2¹⁴ = 81489976247 is a prime.

It is a super-2 number, since 2×81489992631² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81489992641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 131860521 + ... + 131861138.

It is an arithmetic number, because the mean of its divisors is an integer number (13713526320).

Almost surely, 2^81489992631 is an apocalyptic number.

81489992631 is a deficient number, since it is larger than the sum of its proper divisors (28218217929).

81489992631 is a wasteful number, since it uses less digits than its factorization.

81489992631 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 263721765.

The product of its digits is 6718464, while the sum is 60.

The spelling of 81489992631 in words is "eighty-one billion, four hundred eighty-nine million, nine hundred ninety-two thousand, six hundred thirty-one".