20866997 has 8 divisors (see below), whose sum is σ = 22476960. Its totient is φ = 19308240.

The previous prime is 20866969. The next prime is 20867023. The reversal of 20866997 is 79966802.

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 20866997 - 2⁶ = 20866933 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20866907) 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, 11954 + ... + 13587.

It is an arithmetic number, because the mean of its divisors is an integer number (2809620).

Almost surely, 2^20866997 is an apocalyptic number.

It is an amenable number.

20866997 is a deficient number, since it is larger than the sum of its proper divisors (1609963).

20866997 is a wasteful number, since it uses less digits than its factorization.

20866997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25603.

The product of its (nonzero) digits is 326592, while the sum is 47.

The square root of 20866997 is about 4568.0408273132. The cubic root of 20866997 is about 275.3087309570.

The spelling of 20866997 in words is "twenty million, eight hundred sixty-six thousand, nine hundred ninety-seven".