81219431462399 has 32 divisors (see below), whose sum is σ = 83130371850240. Its totient is φ = 79328268343552.

The previous prime is 81219431462363. The next prime is 81219431462431. The reversal of 81219431462399 is 99326413491218.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 81219431462399 - 2¹² = 81219431458303 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 (81219431462359) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 13703292374 + ... + 13703298300.

It is an arithmetic number, because the mean of its divisors is an integer number (2597824120320).

Almost surely, 2^{81219431462399} is an apocalyptic number.

81219431462399 is a deficient number, since it is larger than the sum of its proper divisors (1910940387841).

81219431462399 is a wasteful number, since it uses less digits than its factorization.

81219431462399 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8599.

The product of its digits is 20155392, while the sum is 62.

The spelling of 81219431462399 in words is "eighty-one trillion, two hundred nineteen billion, four hundred thirty-one million, four hundred sixty-two thousand, three hundred ninety-nine".