21039194479 has 2 divisors, whose sum is σ = 21039194480. Its totient is φ = 21039194478.

The previous prime is 21039194453. The next prime is 21039194521. The reversal of 21039194479 is 97449193012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21039194479 - 2¹⁵ = 21039161711 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21039197479) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10519597239 + 10519597240.

It is an arithmetic number, because the mean of its divisors is an integer number (10519597240).

Almost surely, 2^21039194479 is an apocalyptic number.

21039194479 is a deficient number, since it is larger than the sum of its proper divisors (1).

21039194479 is an equidigital number, since it uses as much as digits as its factorization.

21039194479 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 489888, while the sum is 49.

The spelling of 21039194479 in words is "twenty-one billion, thirty-nine million, one hundred ninety-four thousand, four hundred seventy-nine".