21839231491 has 16 divisors (see below), whose sum is σ = 27240288768. Its totient is φ = 17009985600.

The previous prime is 21839231413. The next prime is 21839231497. The reversal of 21839231491 is 19413293812.

It is a cyclic number.

It is not a de Polignac number, because 21839231491 - 2⁹ = 21839230979 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21839231497) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 113466 + ... + 237808.

It is an arithmetic number, because the mean of its divisors is an integer number (1702518048).

Almost surely, 2^21839231491 is an apocalyptic number.

21839231491 is a deficient number, since it is larger than the sum of its proper divisors (5401057277).

21839231491 is a wasteful number, since it uses less digits than its factorization.

21839231491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 126642.

The product of its digits is 93312, while the sum is 43.

The spelling of 21839231491 in words is "twenty-one billion, eight hundred thirty-nine million, two hundred thirty-one thousand, four hundred ninety-one".