20971499 has 4 divisors (see below), whose sum is σ = 20986200. Its totient is φ = 20956800.

The previous prime is 20971493. The next prime is 20971507. The reversal of 20971499 is 99417902.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20971499 - 2²⁰ = 19922923 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20971493) 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, 4949 + ... + 8150.

It is an arithmetic number, because the mean of its divisors is an integer number (5246550).

Almost surely, 2^20971499 is an apocalyptic number.

20971499 is a deficient number, since it is larger than the sum of its proper divisors (14701).

20971499 is a wasteful number, since it uses less digits than its factorization.

20971499 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14700.

The product of its (nonzero) digits is 40824, while the sum is 41.

The square root of 20971499 is about 4579.4649250759. The cubic root of 20971499 is about 275.7675482767.

The spelling of 20971499 in words is "twenty million, nine hundred seventy-one thousand, four hundred ninety-nine".