21426351 has 4 divisors (see below), whose sum is σ = 28568472. Its totient is φ = 14284232.

The previous prime is 21426343. The next prime is 21426359. The reversal of 21426351 is 15362412.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (21426343) and next prime (21426359).

It is a cyclic number.

It is not a de Polignac number, because 21426351 - 2³ = 21426343 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21426359) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3571056 + ... + 3571061.

It is an arithmetic number, because the mean of its divisors is an integer number (7142118).

Almost surely, 2^21426351 is an apocalyptic number.

21426351 is a deficient number, since it is larger than the sum of its proper divisors (7142121).

21426351 is an equidigital number, since it uses as much as digits as its factorization.

21426351 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7142120.

The product of its digits is 1440, while the sum is 24.

The square root of 21426351 is about 4628.8606589527. The cubic root of 21426351 is about 277.7470180991.

Adding to 21426351 its reverse (15362412), we get a palindrome (36788763).

It can be divided in two parts, 214 and 26351, that added together give a triangular number (26565 = T₂₃₀).

The spelling of 21426351 in words is "twenty-one million, four hundred twenty-six thousand, three hundred fifty-one".