81877293 has 12 divisors (see below), whose sum is σ = 122082688. Its totient is φ = 52823880.

The previous prime is 81877249. The next prime is 81877297. The reversal of 81877293 is 39277818.

It is a de Polignac number, because none of the positive numbers 2^k-81877293 is a prime.

It is a super-2 number, since 2×81877293² = 13407782218015698, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81877297) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 146455 + ... + 147012.

Almost surely, 2^81877293 is an apocalyptic number.

It is an amenable number.

81877293 is a deficient number, since it is larger than the sum of its proper divisors (40205395).

81877293 is a wasteful number, since it uses less digits than its factorization.

81877293 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 293504 (or 293501 counting only the distinct ones).

The product of its digits is 169344, while the sum is 45.

The square root of 81877293 is about 9048.6072408962. The cubic root of 81877293 is about 434.2313337699.

The spelling of 81877293 in words is "eighty-one million, eight hundred seventy-seven thousand, two hundred ninety-three".