21948291 has 12 divisors (see below), whose sum is σ = 31744440. Its totient is φ = 14613120.

The previous prime is 21948263. The next prime is 21948293. The reversal of 21948291 is 19284912.

It is not a de Polignac number, because 21948291 - 2⁷ = 21948163 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21948293) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10675 + ... + 12563.

It is an arithmetic number, because the mean of its divisors is an integer number (2645370).

Almost surely, 2^21948291 is an apocalyptic number.

21948291 is a deficient number, since it is larger than the sum of its proper divisors (9796149).

21948291 is a wasteful number, since it uses less digits than its factorization.

21948291 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3186 (or 3183 counting only the distinct ones).

The product of its digits is 10368, while the sum is 36.

The square root of 21948291 is about 4684.9003191103. The cubic root of 21948291 is about 279.9842295540.

The spelling of 21948291 in words is "twenty-one million, nine hundred forty-eight thousand, two hundred ninety-one".