21145985293 has 2 divisors, whose sum is σ = 21145985294. Its totient is φ = 21145985292.

The previous prime is 21145985251. The next prime is 21145985323. The reversal of 21145985293 is 39258954112.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17126171689 + 4019813604 = 130867^2 + 63402^2 .

It is a cyclic number.

It is not a de Polignac number, because 21145985293 - 2¹³ = 21145977101 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21145985233) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10572992646 + 10572992647.

It is an arithmetic number, because the mean of its divisors is an integer number (10572992647).

Almost surely, 2^21145985293 is an apocalyptic number.

It is an amenable number.

21145985293 is a deficient number, since it is larger than the sum of its proper divisors (1).

21145985293 is an equidigital number, since it uses as much as digits as its factorization.

21145985293 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 777600, while the sum is 49.

The spelling of 21145985293 in words is "twenty-one billion, one hundred forty-five million, nine hundred eighty-five thousand, two hundred ninety-three".