21292451 has 8 divisors (see below), whose sum is σ = 21741360. Its totient is φ = 20846592.

The previous prime is 21292441. The next prime is 21292471. The reversal of 21292451 is 15429212.

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 21292451 - 2¹⁰ = 21291427 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21292451.

It is not an unprimeable number, because it can be changed into a prime (21292441) 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, 17891 + ... + 19043.

It is an arithmetic number, because the mean of its divisors is an integer number (2717670).

Almost surely, 2^21292451 is an apocalyptic number.

21292451 is a deficient number, since it is larger than the sum of its proper divisors (448909).

21292451 is a wasteful number, since it uses less digits than its factorization.

21292451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1525.

The product of its digits is 1440, while the sum is 26.

The square root of 21292451 is about 4614.3743887986. The cubic root of 21292451 is about 277.1672325326.

The spelling of 21292451 in words is "twenty-one million, two hundred ninety-two thousand, four hundred fifty-one".