21859458 has 32 divisors (see below), whose sum is σ = 44789760. Its totient is φ = 7110480.

The previous prime is 21859457. The next prime is 21859459. The reversal of 21859458 is 85495812.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21859457) and next prime (21859459).

It is not an unprimeable number, because it can be changed into a prime (21859451) 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, 50503 + ... + 50933.

It is an arithmetic number, because the mean of its divisors is an integer number (1399680).

Almost surely, 2^21859458 is an apocalyptic number.

21859458 is an abundant number, since it is smaller than the sum of its proper divisors (22930302).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21859458 is a wasteful number, since it uses less digits than its factorization.

21859458 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 622.

The product of its digits is 115200, while the sum is 42.

The square root of 21859458 is about 4675.4099285517. The cubic root of 21859458 is about 279.6059849190.

The spelling of 21859458 in words is "twenty-one million, eight hundred fifty-nine thousand, four hundred fifty-eight".