21246331 has 4 divisors (see below), whose sum is σ = 21265912. Its totient is φ = 21226752.

The previous prime is 21246317. The next prime is 21246341. The reversal of 21246331 is 13364212.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21246331 is a prime.

It is a super-2 number, since 2×21246331² = 902813161923122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21246341) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8061 + ... + 10366.

It is an arithmetic number, because the mean of its divisors is an integer number (5316478).

Almost surely, 2^21246331 is an apocalyptic number.

21246331 is a deficient number, since it is larger than the sum of its proper divisors (19581).

21246331 is a wasteful number, since it uses less digits than its factorization.

21246331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19580.

The product of its digits is 864, while the sum is 22.

The square root of 21246331 is about 4609.3742525423. The cubic root of 21246331 is about 276.9669707389.

The spelling of 21246331 in words is "twenty-one million, two hundred forty-six thousand, three hundred thirty-one".