81393417 has 20 divisors (see below), whose sum is σ = 138958336. Its totient is φ = 46510200.

The previous prime is 81393413. The next prime is 81393419. The reversal of 81393417 is 71439318.

It is a happy number.

It is not a de Polignac number, because 81393417 - 2² = 81393413 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81393413) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 71209 + ... + 72342.

Almost surely, 2^81393417 is an apocalyptic number.

It is an amenable number.

81393417 is a deficient number, since it is larger than the sum of its proper divisors (57564919).

81393417 is a wasteful number, since it uses less digits than its factorization.

81393417 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 143570 (or 143561 counting only the distinct ones).

The product of its digits is 18144, while the sum is 36.

The square root of 81393417 is about 9021.8300250005. The cubic root of 81393417 is about 433.3742406484.

It can be divided in two parts, 81393 and 417, that added together give a triangular number (81810 = T₄₀₄).

The spelling of 81393417 in words is "eighty-one million, three hundred ninety-three thousand, four hundred seventeen".