21257379959 has 8 divisors (see below), whose sum is σ = 21552984768. Its totient is φ = 20963335680.

The previous prime is 21257379937. The next prime is 21257380013. The reversal of 21257379959 is 95997375212.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21257379959 - 2¹² = 21257375863 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21257379898 and 21257379907.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21257379259) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 362687 + ... + 417200.

It is an arithmetic number, because the mean of its divisors is an integer number (2694123096).

Almost surely, 2^21257379959 is an apocalyptic number.

21257379959 is a deficient number, since it is larger than the sum of its proper divisors (295604809).

21257379959 is an equidigital number, since it uses as much as digits as its factorization.

21257379959 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 780265.

The product of its digits is 10716300, while the sum is 59.

The spelling of 21257379959 in words is "twenty-one billion, two hundred fifty-seven million, three hundred seventy-nine thousand, nine hundred fifty-nine".