21953459 has 4 divisors (see below), whose sum is σ = 23949240. Its totient is φ = 19957680.

The previous prime is 21953447. The next prime is 21953471. The reversal of 21953459 is 95435912.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (21953447) and next prime (21953471).

It is a cyclic number.

It is not a de Polignac number, because 21953459 - 2²⁴ = 5176243 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21953419) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 997874 + ... + 997895.

It is an arithmetic number, because the mean of its divisors is an integer number (5987310).

Almost surely, 2^21953459 is an apocalyptic number.

21953459 is a deficient number, since it is larger than the sum of its proper divisors (1995781).

21953459 is a wasteful number, since it uses less digits than its factorization.

21953459 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1995780.

The product of its digits is 48600, while the sum is 38.

The square root of 21953459 is about 4685.4518458736. The cubic root of 21953459 is about 280.0062030939.

The spelling of 21953459 in words is "twenty-one million, nine hundred fifty-three thousand, four hundred fifty-nine".