21452731 has 2 divisors, whose sum is σ = 21452732. Its totient is φ = 21452730.

The previous prime is 21452701. The next prime is 21452741. The reversal of 21452731 is 13725412.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21452731 - 2⁵ = 21452699 is a prime.

It is a super-2 number, since 2×21452731² = 920439334716722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21452696 and 21452705.

It is not a weakly prime, because it can be changed into another prime (21452701) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10726365 + 10726366.

It is an arithmetic number, because the mean of its divisors is an integer number (10726366).

Almost surely, 2^21452731 is an apocalyptic number.

21452731 is a deficient number, since it is larger than the sum of its proper divisors (1).

21452731 is an equidigital number, since it uses as much as digits as its factorization.

21452731 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1680, while the sum is 25.

The square root of 21452731 is about 4631.7092957136. The cubic root of 21452731 is about 277.8609581944.

The spelling of 21452731 in words is "twenty-one million, four hundred fifty-two thousand, seven hundred thirty-one".