81370349 has 4 divisors (see below), whose sum is σ = 81407040. Its totient is φ = 81333660.

The previous prime is 81370339. The next prime is 81370379. The reversal of 81370349 is 94307318.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81370349 is a prime.

It is a super-2 number, since 2×81370349² = 13242267392763602, 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 (81370339) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14789 + ... + 19530.

It is an arithmetic number, because the mean of its divisors is an integer number (20351760).

Almost surely, 2^81370349 is an apocalyptic number.

It is an amenable number.

81370349 is a deficient number, since it is larger than the sum of its proper divisors (36691).

81370349 is a wasteful number, since it uses less digits than its factorization.

81370349 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36690.

The product of its (nonzero) digits is 18144, while the sum is 35.

The square root of 81370349 is about 9020.5514798154. The cubic root of 81370349 is about 433.3332953978. Note that the first 3 decimals are identical.

The spelling of 81370349 in words is "eighty-one million, three hundred seventy thousand, three hundred forty-nine".