21232412491 has 4 divisors (see below), whose sum is σ = 21385163800. Its totient is φ = 21079661184.

The previous prime is 21232412489. The next prime is 21232412503. The reversal of 21232412491 is 19421423212.

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 21232412491 - 2¹ = 21232412489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21232412431) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 76375446 + ... + 76375723.

It is an arithmetic number, because the mean of its divisors is an integer number (5346290950).

Almost surely, 2^21232412491 is an apocalyptic number.

21232412491 is a deficient number, since it is larger than the sum of its proper divisors (152751309).

21232412491 is a wasteful number, since it uses less digits than its factorization.

21232412491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 152751308.

The product of its digits is 6912, while the sum is 31.

The spelling of 21232412491 in words is "twenty-one billion, two hundred thirty-two million, four hundred twelve thousand, four hundred ninety-one".