21240693 has 12 divisors (see below), whose sum is σ = 30871360. Its totient is φ = 14072616.

The previous prime is 21240683. The next prime is 21240697. The reversal of 21240693 is 39604212.

It is not a de Polignac number, because 21240693 - 2¹⁸ = 20978549 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21240697) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5773 + ... + 8706.

Almost surely, 2^21240693 is an apocalyptic number.

It is an amenable number.

21240693 is a deficient number, since it is larger than the sum of its proper divisors (9630667).

21240693 is a wasteful number, since it uses less digits than its factorization.

21240693 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14648 (or 14645 counting only the distinct ones).

The product of its (nonzero) digits is 2592, while the sum is 27.

The square root of 21240693 is about 4608.7626322040. The cubic root of 21240693 is about 276.9424695999.

The spelling of 21240693 in words is "twenty-one million, two hundred forty thousand, six hundred ninety-three".