81902397 has 8 divisors (see below), whose sum is σ = 109553344. Its totient is φ = 54426528.

The previous prime is 81902377. The next prime is 81902399. The reversal of 81902397 is 79320918.

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

It is not a de Polignac number, because 81902397 - 2⁷ = 81902269 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 (81902399) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 42673 + ... + 44550.

It is an arithmetic number, because the mean of its divisors is an integer number (13694168).

Almost surely, 2^81902397 is an apocalyptic number.

It is an amenable number.

81902397 is a deficient number, since it is larger than the sum of its proper divisors (27650947).

81902397 is a wasteful number, since it uses less digits than its factorization.

81902397 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 87539.

The product of its (nonzero) digits is 27216, while the sum is 39.

The square root of 81902397 is about 9049.9943093905. The cubic root of 81902397 is about 434.2757084233.

The spelling of 81902397 in words is "eighty-one million, nine hundred two thousand, three hundred ninety-seven".