21150420493 has 2 divisors, whose sum is σ = 21150420494. Its totient is φ = 21150420492.

The previous prime is 21150420481. The next prime is 21150420553. The reversal of 21150420493 is 39402405112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19712721604 + 1437698889 = 140402^2 + 37917^2 .

It is a cyclic number.

It is not a de Polignac number, because 21150420493 - 2²⁵ = 21116866061 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21150421493) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10575210246 + 10575210247.

It is an arithmetic number, because the mean of its divisors is an integer number (10575210247).

Almost surely, 2^21150420493 is an apocalyptic number.

It is an amenable number.

21150420493 is a deficient number, since it is larger than the sum of its proper divisors (1).

21150420493 is an equidigital number, since it uses as much as digits as its factorization.

21150420493 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8640, while the sum is 31.

The spelling of 21150420493 in words is "twenty-one billion, one hundred fifty million, four hundred twenty thousand, four hundred ninety-three".