21454329989 has 2 divisors, whose sum is σ = 21454329990. Its totient is φ = 21454329988.

The previous prime is 21454329961. The next prime is 21454330031. The reversal of 21454329989 is 98992345412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 12008433889 + 9445896100 = 109583^2 + 97190^2 .

It is a cyclic number.

It is not a de Polignac number, because 21454329989 - 2²⁸ = 21185894533 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21454329889) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10727164994 + 10727164995.

It is an arithmetic number, because the mean of its divisors is an integer number (10727164995).

Almost surely, 2^21454329989 is an apocalyptic number.

It is an amenable number.

21454329989 is a deficient number, since it is larger than the sum of its proper divisors (1).

21454329989 is an equidigital number, since it uses as much as digits as its factorization.

21454329989 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5598720, while the sum is 56.

The spelling of 21454329989 in words is "twenty-one billion, four hundred fifty-four million, three hundred twenty-nine thousand, nine hundred eighty-nine".