81902015 has 8 divisors (see below), whose sum is σ = 105842688. Its totient is φ = 60481440.

The previous prime is 81901991. The next prime is 81902017. The reversal of 81902015 is 51020918.

It is a happy number.

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

It is not a de Polignac number, because 81902015 - 2²⁰ = 80853439 is a prime.

It is a super-2 number, since 2×81902015² = 13415880122120450, 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 (81902017) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 629951 + ... + 630080.

It is an arithmetic number, because the mean of its divisors is an integer number (13230336).

Almost surely, 2^81902015 is an apocalyptic number.

81902015 is a deficient number, since it is larger than the sum of its proper divisors (23940673).

81902015 is a wasteful number, since it uses less digits than its factorization.

81902015 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1260049.

The product of its (nonzero) digits is 720, while the sum is 26.

The square root of 81902015 is about 9049.9732043802. The cubic root of 81902015 is about 434.2750332555.

The spelling of 81902015 in words is "eighty-one million, nine hundred two thousand, fifteen".