21368451 has 8 divisors (see below), whose sum is σ = 30682960. Its totient is φ = 13149792.

The previous prime is 21368429. The next prime is 21368453. The reversal of 21368451 is 15486312.

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

It is not a de Polignac number, because 21368451 - 2⁶ = 21368387 is a prime.

It is a super-2 number, since 2×21368451² = 913221396278802, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21368453) 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, 273916 + ... + 273993.

It is an arithmetic number, because the mean of its divisors is an integer number (3835370).

Almost surely, 2^21368451 is an apocalyptic number.

21368451 is a deficient number, since it is larger than the sum of its proper divisors (9314509).

21368451 is a wasteful number, since it uses less digits than its factorization.

21368451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 547925.

The product of its digits is 5760, while the sum is 30.

The square root of 21368451 is about 4622.6021892436. The cubic root of 21368451 is about 277.4966090000.

The spelling of 21368451 in words is "twenty-one million, three hundred sixty-eight thousand, four hundred fifty-one".