21291862 has 4 divisors (see below), whose sum is σ = 31937796. Its totient is φ = 10645930.

The previous prime is 21291847. The next prime is 21291883. The reversal of 21291862 is 26819212.

It is a semiprime because it is the product of two primes.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5322964 + ... + 5322967.

It is an arithmetic number, because the mean of its divisors is an integer number (7984449).

Almost surely, 2^21291862 is an apocalyptic number.

21291862 is a deficient number, since it is larger than the sum of its proper divisors (10645934).

21291862 is a wasteful number, since it uses less digits than its factorization.

21291862 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10645933.

The product of its digits is 3456, while the sum is 31.

The square root of 21291862 is about 4614.3105660543. The cubic root of 21291862 is about 277.1646768067.

The spelling of 21291862 in words is "twenty-one million, two hundred ninety-one thousand, eight hundred sixty-two".