21451430629 has 2 divisors, whose sum is σ = 21451430630. Its totient is φ = 21451430628.

The previous prime is 21451430573. The next prime is 21451430687. The reversal of 21451430629 is 92603415412.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 17062368129 + 4389062500 = 130623^2 + 66250^2 .

It is a cyclic number.

It is not a de Polignac number, because 21451430629 - 2¹⁷ = 21451299557 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21451439629) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10725715314 + 10725715315.

It is an arithmetic number, because the mean of its divisors is an integer number (10725715315).

Almost surely, 2^21451430629 is an apocalyptic number.

It is an amenable number.

21451430629 is a deficient number, since it is larger than the sum of its proper divisors (1).

21451430629 is an equidigital number, since it uses as much as digits as its factorization.

21451430629 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 51840, while the sum is 37.

The spelling of 21451430629 in words is "twenty-one billion, four hundred fifty-one million, four hundred thirty thousand, six hundred twenty-nine".