21320254 has 4 divisors (see below), whose sum is σ = 31980384. Its totient is φ = 10660126.

The previous prime is 21320239. The next prime is 21320267. The reversal of 21320254 is 45202312.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5330062 + ... + 5330065.

It is an arithmetic number, because the mean of its divisors is an integer number (7995096).

Almost surely, 2^21320254 is an apocalyptic number.

21320254 is a deficient number, since it is larger than the sum of its proper divisors (10660130).

21320254 is a wasteful number, since it uses less digits than its factorization.

21320254 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10660129.

The product of its (nonzero) digits is 480, while the sum is 19.

The square root of 21320254 is about 4617.3860570674. The cubic root of 21320254 is about 277.2878187579.

Adding to 21320254 its reverse (45202312), we get a palindrome (66522566).

The spelling of 21320254 in words is "twenty-one million, three hundred twenty thousand, two hundred fifty-four".