21240508 has 6 divisors (see below), whose sum is σ = 37170896. Its totient is φ = 10620252.

The previous prime is 21240433. The next prime is 21240511. The reversal of 21240508 is 80504212.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2655060 + ... + 2655067.

Almost surely, 2^21240508 is an apocalyptic number.

It is an amenable number.

21240508 is a deficient number, since it is larger than the sum of its proper divisors (15930388).

21240508 is a wasteful number, since it uses less digits than its factorization.

21240508 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5310131 (or 5310129 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 22.

The square root of 21240508 is about 4608.7425616973. The cubic root of 21240508 is about 276.9416655692.

The spelling of 21240508 in words is "twenty-one million, two hundred forty thousand, five hundred eight".