20916247 has 8 divisors (see below), whose sum is σ = 22901760. Its totient is φ = 18944760.

The previous prime is 20916241. The next prime is 20916251. The reversal of 20916247 is 74261902.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20916247 - 2¹⁵ = 20883479 is a prime.

It is a super-3 number, since 3×20916247³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20916241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 247 + ... + 6472.

It is an arithmetic number, because the mean of its divisors is an integer number (2862720).

Almost surely, 2^20916247 is an apocalyptic number.

20916247 is a deficient number, since it is larger than the sum of its proper divisors (1985513).

20916247 is a wasteful number, since it uses less digits than its factorization.

20916247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7013.

The product of its (nonzero) digits is 6048, while the sum is 31.

The square root of 20916247 is about 4573.4283639301. The cubic root of 20916247 is about 275.5251540763.

It can be divided in two parts, 2091 and 6247, that added together give a palindrome (8338).

The spelling of 20916247 in words is "twenty million, nine hundred sixteen thousand, two hundred forty-seven".