21503869579 has 2 divisors, whose sum is σ = 21503869580. Its totient is φ = 21503869578.

The previous prime is 21503869459. The next prime is 21503869637. The reversal of 21503869579 is 97596830512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21503869579 - 2⁷ = 21503869451 is a prime.

It is not a weakly prime, because it can be changed into another prime (21503869979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10751934789 + 10751934790.

It is an arithmetic number, because the mean of its divisors is an integer number (10751934790).

Almost surely, 2^21503869579 is an apocalyptic number.

21503869579 is a deficient number, since it is larger than the sum of its proper divisors (1).

21503869579 is an equidigital number, since it uses as much as digits as its factorization.

21503869579 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4082400, while the sum is 55.

The spelling of 21503869579 in words is "twenty-one billion, five hundred three million, eight hundred sixty-nine thousand, five hundred seventy-nine".