81512369 has 8 divisors (see below), whose sum is σ = 83867520. Its totient is φ = 79165296.

The previous prime is 81512363. The next prime is 81512371. The reversal of 81512369 is 96321518.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81512369 is a prime.

It is a super-2 number, since 2×81512369² = 13288532599984322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81512363) 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, 22712 + ... + 26054.

It is an arithmetic number, because the mean of its divisors is an integer number (10483440).

Almost surely, 2^81512369 is an apocalyptic number.

It is an amenable number.

81512369 is a deficient number, since it is larger than the sum of its proper divisors (2355151).

81512369 is a wasteful number, since it uses less digits than its factorization.

81512369 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4039.

The product of its digits is 12960, while the sum is 35.

The square root of 81512369 is about 9028.4200721942. The cubic root of 81512369 is about 433.5852554212.

The spelling of 81512369 in words is "eighty-one million, five hundred twelve thousand, three hundred sixty-nine".