81773397 has 12 divisors (see below), whose sum is σ = 124334080. Its totient is φ = 51646248.

The previous prime is 81773371. The next prime is 81773413. The reversal of 81773397 is 79337718.

It is not a de Polignac number, because 81773397 - 2⁷ = 81773269 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81773317) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 238933 + ... + 239274.

Almost surely, 2^81773397 is an apocalyptic number.

It is an amenable number.

81773397 is a deficient number, since it is larger than the sum of its proper divisors (42560683).

81773397 is a wasteful number, since it uses less digits than its factorization.

81773397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 478232 (or 478229 counting only the distinct ones).

The product of its digits is 222264, while the sum is 45.

The square root of 81773397 is about 9042.8644245062. The cubic root of 81773397 is about 434.0475872841.

The spelling of 81773397 in words is "eighty-one million, seven hundred seventy-three thousand, three hundred ninety-seven".