21799958257 has 16 divisors (see below), whose sum is σ = 27913744512. Its totient is φ = 16527870720.

The previous prime is 21799958249. The next prime is 21799958261. The reversal of 21799958257 is 75285999712.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21799958257 - 2³ = 21799958249 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21799958207) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3823048 + ... + 3828745.

It is an arithmetic number, because the mean of its divisors is an integer number (1744609032).

Almost surely, 2^21799958257 is an apocalyptic number.

It is an amenable number.

21799958257 is a deficient number, since it is larger than the sum of its proper divisors (6113786255).

21799958257 is a wasteful number, since it uses less digits than its factorization.

21799958257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7651848.

The product of its digits is 28576800, while the sum is 64.

The spelling of 21799958257 in words is "twenty-one billion, seven hundred ninety-nine million, nine hundred fifty-eight thousand, two hundred fifty-seven".