21954291 has 16 divisors (see below), whose sum is σ = 30944640. Its totient is φ = 13806720.

The previous prime is 21954287. The next prime is 21954299. The reversal of 21954291 is 19245912.

It is not a de Polignac number, because 21954291 - 2² = 21954287 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21954299) 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, 15451 + ... + 16811.

It is an arithmetic number, because the mean of its divisors is an integer number (1934040).

Almost surely, 2^21954291 is an apocalyptic number.

21954291 is a deficient number, since it is larger than the sum of its proper divisors (8990349).

21954291 is a wasteful number, since it uses less digits than its factorization.

21954291 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1666.

The product of its digits is 6480, while the sum is 33.

The square root of 21954291 is about 4685.5406304929. The cubic root of 21954291 is about 280.0097403074.

The spelling of 21954291 in words is "twenty-one million, nine hundred fifty-four thousand, two hundred ninety-one".