21476431 has 2 divisors, whose sum is σ = 21476432. Its totient is φ = 21476430.

The previous prime is 21476419. The next prime is 21476447. The reversal of 21476431 is 13467412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21476431 - 2⁷ = 21476303 is a prime.

It is a super-2 number, since 2×21476431² = 922474176995522, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21476431.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21476401) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10738215 + 10738216.

It is an arithmetic number, because the mean of its divisors is an integer number (10738216).

Almost surely, 2^21476431 is an apocalyptic number.

21476431 is a deficient number, since it is larger than the sum of its proper divisors (1).

21476431 is an equidigital number, since it uses as much as digits as its factorization.

21476431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4032, while the sum is 28.

The square root of 21476431 is about 4634.2670402125. The cubic root of 21476431 is about 277.9632432468.

The spelling of 21476431 in words is "twenty-one million, four hundred seventy-six thousand, four hundred thirty-one".