21406697292 has 12 divisors (see below), whose sum is σ = 49948960376. Its totient is φ = 7135565760.

The previous prime is 21406697233. The next prime is 21406697359. The reversal of 21406697292 is 29279660412.

It is a tau number, because it is divible by the number of its divisors (12).

It is an unprimeable number.

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, 891945709 + ... + 891945732.

Almost surely, 2^21406697292 is an apocalyptic number.

It is an amenable number.

21406697292 is an abundant number, since it is smaller than the sum of its proper divisors (28542263084).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21406697292 is a wasteful number, since it uses less digits than its factorization.

21406697292 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1783891448 (or 1783891446 counting only the distinct ones).

The product of its (nonzero) digits is 653184, while the sum is 48.

The spelling of 21406697292 in words is "twenty-one billion, four hundred six million, six hundred ninety-seven thousand, two hundred ninety-two".