20958247 has 4 divisors (see below), whose sum is σ = 21210840. Its totient is φ = 20705656.

The previous prime is 20958241. The next prime is 20958251. The reversal of 20958247 is 74285902.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 74285902 = 2 ⋅37142951.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20958247 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 (20958241) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 126172 + ... + 126337.

It is an arithmetic number, because the mean of its divisors is an integer number (5302710).

Almost surely, 2^20958247 is an apocalyptic number.

20958247 is a deficient number, since it is larger than the sum of its proper divisors (252593).

20958247 is an equidigital number, since it uses as much as digits as its factorization.

20958247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 252592.

The product of its (nonzero) digits is 40320, while the sum is 37.

The square root of 20958247 is about 4578.0178024992. The cubic root of 20958247 is about 275.7094497182.

The spelling of 20958247 in words is "twenty million, nine hundred fifty-eight thousand, two hundred forty-seven".