21338451 has 16 divisors (see below), whose sum is σ = 33472800. Its totient is φ = 13388544.

The previous prime is 21338441. The next prime is 21338467. The reversal of 21338451 is 15483312.

It is a happy number.

It is not a de Polignac number, because 21338451 - 2¹³ = 21330259 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (21338431) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22786 + ... + 23703.

It is an arithmetic number, because the mean of its divisors is an integer number (2092050).

Almost surely, 2^21338451 is an apocalyptic number.

21338451 is a deficient number, since it is larger than the sum of its proper divisors (12134349).

21338451 is a wasteful number, since it uses less digits than its factorization.

21338451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46515 (or 46509 counting only the distinct ones).

The product of its digits is 2880, while the sum is 27.

The square root of 21338451 is about 4619.3561239636. The cubic root of 21338451 is about 277.3666854164.

The spelling of 21338451 in words is "twenty-one million, three hundred thirty-eight thousand, four hundred fifty-one".