21258653197 has 8 divisors (see below), whose sum is σ = 21406593600. Its totient is φ = 21111124320.

The previous prime is 21258653191. The next prime is 21258653219. The reversal of 21258653197 is 79135685212.

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 21258653197 - 2⁷ = 21258653069 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21258653197.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21258653191) 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, 1158 + ... + 206200.

It is an arithmetic number, because the mean of its divisors is an integer number (2675824200).

Almost surely, 2^21258653197 is an apocalyptic number.

It is an amenable number.

21258653197 is a deficient number, since it is larger than the sum of its proper divisors (147940403).

21258653197 is a wasteful number, since it uses less digits than its factorization.

21258653197 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 205763.

The product of its digits is 907200, while the sum is 49.

The spelling of 21258653197 in words is "twenty-one billion, two hundred fifty-eight million, six hundred fifty-three thousand, one hundred ninety-seven".