21952261 has 8 divisors (see below), whose sum is σ = 22567104. Its totient is φ = 21341280.

The previous prime is 21952207. The next prime is 21952291. The reversal of 21952261 is 16225912.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21952261 - 2⁹ = 21951749 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21952291) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13456 + ... + 14998.

It is an arithmetic number, because the mean of its divisors is an integer number (2820888).

Almost surely, 2^21952261 is an apocalyptic number.

It is an amenable number.

21952261 is a deficient number, since it is larger than the sum of its proper divisors (614843).

21952261 is a wasteful number, since it uses less digits than its factorization.

21952261 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1931.

The product of its digits is 2160, while the sum is 28.

The square root of 21952261 is about 4685.3240016033. The cubic root of 21952261 is about 280.0011096895.

The spelling of 21952261 in words is "twenty-one million, nine hundred fifty-two thousand, two hundred sixty-one".