21479765797 has 8 divisors (see below), whose sum is σ = 24844067136. Its totient is φ = 18189405312.

The previous prime is 21479765789. The next prime is 21479765809. The reversal of 21479765797 is 79756797412.

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 21479765797 - 2³ = 21479765789 is a prime.

It is a super-2 number, since 2×21479765797² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21479765737) 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, 18484588 + ... + 18485749.

It is an arithmetic number, because the mean of its divisors is an integer number (3105508392).

Almost surely, 2^21479765797 is an apocalyptic number.

It is an amenable number.

21479765797 is a deficient number, since it is larger than the sum of its proper divisors (3364301339).

21479765797 is an equidigital number, since it uses as much as digits as its factorization.

21479765797 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36970427.

The product of its digits is 46675440, while the sum is 64.

The spelling of 21479765797 in words is "twenty-one billion, four hundred seventy-nine million, seven hundred sixty-five thousand, seven hundred ninety-seven".