21234290 has 96 divisors (see below), whose sum is σ = 50561280. Its totient is φ = 6272640.

The previous prime is 21234281. The next prime is 21234299. The reversal of 21234290 is 9243212.

It is an interprime number because it is at equal distance from previous prime (21234281) and next prime (21234299).

It is a Harshad number since it is a multiple of its sum of digits (23).

It is not an unprimeable number, because it can be changed into a prime (21234299) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 194756 + ... + 194864.

It is an arithmetic number, because the mean of its divisors is an integer number (526680).

Almost surely, 2^21234290 is an apocalyptic number.

21234290 is an abundant number, since it is smaller than the sum of its proper divisors (29326990).

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

21234290 is a wasteful number, since it uses less digits than its factorization.

21234290 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 168 (or 157 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 23.

The square root of 21234290 is about 4608.0679248466. The cubic root of 21234290 is about 276.9146387307.

The spelling of 21234290 in words is "twenty-one million, two hundred thirty-four thousand, two hundred ninety".