21954617 has 4 divisors (see below), whose sum is σ = 22127616. Its totient is φ = 21781620.

The previous prime is 21954613. The next prime is 21954623. The reversal of 21954617 is 71645912.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21954617 - 2² = 21954613 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21954613) 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, 86309 + ... + 86562.

It is an arithmetic number, because the mean of its divisors is an integer number (5531904).

Almost surely, 2^21954617 is an apocalyptic number.

It is an amenable number.

21954617 is a deficient number, since it is larger than the sum of its proper divisors (172999).

21954617 is a wasteful number, since it uses less digits than its factorization.

21954617 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 172998.

The product of its digits is 15120, while the sum is 35.

The square root of 21954617 is about 4685.5754182384. The cubic root of 21954617 is about 280.0111262586.

The spelling of 21954617 in words is "twenty-one million, nine hundred fifty-four thousand, six hundred seventeen".