21240262 has 4 divisors (see below), whose sum is σ = 31860396. Its totient is φ = 10620130.

The previous prime is 21240253. The next prime is 21240283. The reversal of 21240262 is 26204212.

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

It is a super-2 number, since 2×21240262² = 902297459657288, which contains 22 as substring.

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, 5310064 + ... + 5310067.

It is an arithmetic number, because the mean of its divisors is an integer number (7965099).

Almost surely, 2^21240262 is an apocalyptic number.

21240262 is a deficient number, since it is larger than the sum of its proper divisors (10620134).

21240262 is a wasteful number, since it uses less digits than its factorization.

21240262 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10620133.

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 21240262 is about 4608.7158732124. The cubic root of 21240262 is about 276.9405964185.

Adding to 21240262 its reverse (26204212), we get a palindrome (47444474).

The spelling of 21240262 in words is "twenty-one million, two hundred forty thousand, two hundred sixty-two".