21953441 has 4 divisors (see below), whose sum is σ = 21966000. Its totient is φ = 21940884.

The previous prime is 21953419. The next prime is 21953447. The reversal of 21953441 is 14435912.

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 a de Polignac number, because none of the positive numbers 2^k-21953441 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21953447) 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, 3131 + ... + 7328.

It is an arithmetic number, because the mean of its divisors is an integer number (5491500).

Almost surely, 2^21953441 is an apocalyptic number.

It is an amenable number.

21953441 is a deficient number, since it is larger than the sum of its proper divisors (12559).

21953441 is a wasteful number, since it uses less digits than its factorization.

21953441 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12558.

The product of its digits is 4320, while the sum is 29.

The square root of 21953441 is about 4685.4499250339. The cubic root of 21953441 is about 280.0061265666.

The spelling of 21953441 in words is "twenty-one million, nine hundred fifty-three thousand, four hundred forty-one".