21258393166 has 16 divisors (see below), whose sum is σ = 32072171040. Its totient is φ = 10567700640.

The previous prime is 21258393059. The next prime is 21258393197. The reversal of 21258393166 is 66139385212.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2517840 + ... + 2526268.

It is an arithmetic number, because the mean of its divisors is an integer number (2004510690).

Almost surely, 2^21258393166 is an apocalyptic number.

21258393166 is a deficient number, since it is larger than the sum of its proper divisors (10813777874).

21258393166 is a wasteful number, since it uses less digits than its factorization.

21258393166 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15579.

The product of its digits is 466560, while the sum is 46.

The spelling of 21258393166 in words is "twenty-one billion, two hundred fifty-eight million, three hundred ninety-three thousand, one hundred sixty-six".