21401451 has 6 divisors (see below), whose sum is σ = 30913220. Its totient is φ = 14267628.

The previous prime is 21401447. The next prime is 21401461. The reversal of 21401451 is 15410412.

21401451 is a `hidden beast` number, since 214 + 0 + 1 + 451 = 666.

It is not a de Polignac number, because 21401451 - 2² = 21401447 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21401441) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1188961 + ... + 1188978.

Almost surely, 2^21401451 is an apocalyptic number.

21401451 is a deficient number, since it is larger than the sum of its proper divisors (9511769).

21401451 is a wasteful number, since it uses less digits than its factorization.

21401451 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2377945 (or 2377942 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 18.

The square root of 21401451 is about 4626.1702303309. The cubic root of 21401451 is about 277.6393845670.

Adding to 21401451 its reverse (15410412), we get a palindrome (36811863).

The spelling of 21401451 in words is "twenty-one million, four hundred one thousand, four hundred fifty-one".