20993247 has 24 divisors (see below), whose sum is σ = 33712848. Its totient is φ = 12480000.

The previous prime is 20993239. The next prime is 20993257. The reversal of 20993247 is 74239902.

It is not a de Polignac number, because 20993247 - 2³ = 20993239 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20993207) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3247 + ... + 7247.

It is an arithmetic number, because the mean of its divisors is an integer number (1404702).

Almost surely, 2^20993247 is an apocalyptic number.

20993247 is a deficient number, since it is larger than the sum of its proper divisors (12719601).

20993247 is a wasteful number, since it uses less digits than its factorization.

20993247 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4071 (or 4068 counting only the distinct ones).

The product of its (nonzero) digits is 27216, while the sum is 36.

The square root of 20993247 is about 4581.8388230055. The cubic root of 20993247 is about 275.8628414280.

The spelling of 20993247 in words is "twenty million, nine hundred ninety-three thousand, two hundred forty-seven".