21423553491 has 8 divisors (see below), whose sum is σ = 28847557584. Its totient is φ = 14140959200.

The previous prime is 21423553477. The next prime is 21423553507. The reversal of 21423553491 is 19435532412.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21423553491 - 2¹⁹ = 21423029203 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21423553421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 35352096 + ... + 35352701.

It is an arithmetic number, because the mean of its divisors is an integer number (3605944698).

Almost surely, 2^21423553491 is an apocalyptic number.

21423553491 is a deficient number, since it is larger than the sum of its proper divisors (7424004093).

21423553491 is a wasteful number, since it uses less digits than its factorization.

21423553491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70704901.

The product of its digits is 129600, while the sum is 39.

The spelling of 21423553491 in words is "twenty-one billion, four hundred twenty-three million, five hundred fifty-three thousand, four hundred ninety-one".