21651404499 has 36 divisors (see below), whose sum is σ = 32863909624. Its totient is φ = 13734572544.

The previous prime is 21651404491. The next prime is 21651404503. The reversal of 21651404499 is 99440415612.

21651404499 is a `hidden beast` number, since 2 + 1 + 6 + 514 + 0 + 44 + 99 = 666.

It is not a de Polignac number, because 21651404499 - 2³ = 21651404491 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21651404491) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 907092 + ... + 930654.

Almost surely, 2^21651404499 is an apocalyptic number.

21651404499 is a deficient number, since it is larger than the sum of its proper divisors (11212505125).

21651404499 is a wasteful number, since it uses less digits than its factorization.

21651404499 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23808 (or 23782 counting only the distinct ones).

The product of its (nonzero) digits is 311040, while the sum is 45.

The spelling of 21651404499 in words is "twenty-one billion, six hundred fifty-one million, four hundred four thousand, four hundred ninety-nine".