20823987 has 8 divisors (see below), whose sum is σ = 27808704. Its totient is φ = 13860968.

The previous prime is 20823977. The next prime is 20824043. The reversal of 20823987 is 78932802.

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 20823987 - 2¹⁸ = 20561843 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20823937) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3033 + ... + 7130.

It is an arithmetic number, because the mean of its divisors is an integer number (3476088).

Almost surely, 2^20823987 is an apocalyptic number.

20823987 is a deficient number, since it is larger than the sum of its proper divisors (6984717).

20823987 is a wasteful number, since it uses less digits than its factorization.

20823987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10849.

The product of its (nonzero) digits is 48384, while the sum is 39.

The square root of 20823987 is about 4563.3306915015. The cubic root of 20823987 is about 275.1194500361.

The spelling of 20823987 in words is "twenty million, eight hundred twenty-three thousand, nine hundred eighty-seven".