81499415311 has 4 divisors (see below), whose sum is σ = 83233445472. Its totient is φ = 79765385152.

The previous prime is 81499415287. The next prime is 81499415341. The reversal of 81499415311 is 11351499418.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 81499415311 - 2⁵ = 81499415279 is a prime.

It is a super-2 number, since 2×81499415311² (a number of 23 digits) 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 (81499415341) 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, 867015010 + ... + 867015103.

It is an arithmetic number, because the mean of its divisors is an integer number (20808361368).

Almost surely, 2^81499415311 is an apocalyptic number.

81499415311 is a deficient number, since it is larger than the sum of its proper divisors (1734030161).

81499415311 is a wasteful number, since it uses less digits than its factorization.

81499415311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1734030160.

The product of its digits is 155520, while the sum is 46.

The spelling of 81499415311 in words is "eighty-one billion, four hundred ninety-nine million, four hundred fifteen thousand, three hundred eleven".