21354669491 has 8 divisors (see below), whose sum is σ = 21555428400. Its totient is φ = 21153998880.

The previous prime is 21354669463. The next prime is 21354669541. The reversal of 21354669491 is 19496645312.

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 21354669491 - 2³⁴ = 4174800307 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21354669431) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 527780 + ... + 566798.

It is an arithmetic number, because the mean of its divisors is an integer number (2694428550).

Almost surely, 2^21354669491 is an apocalyptic number.

21354669491 is a deficient number, since it is larger than the sum of its proper divisors (200758909).

21354669491 is a wasteful number, since it uses less digits than its factorization.

21354669491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44149.

The product of its digits is 1399680, while the sum is 50.

The spelling of 21354669491 in words is "twenty-one billion, three hundred fifty-four million, six hundred sixty-nine thousand, four hundred ninety-one".