20861897 has 24 divisors (see below), whose sum is σ = 25707456. Its totient is φ = 16846368.

The previous prime is 20861891. The next prime is 20861899. The reversal of 20861897 is 79816802.

It is not a de Polignac number, because 20861897 - 2⁶ = 20861833 is a prime.

It is a super-3 number, since 3×20861897³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20861891) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 120503 + ... + 120675.

It is an arithmetic number, because the mean of its divisors is an integer number (1071144).

Almost surely, 2^20861897 is an apocalyptic number.

It is an amenable number.

20861897 is a deficient number, since it is larger than the sum of its proper divisors (4845559).

20861897 is a wasteful number, since it uses less digits than its factorization.

20861897 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 317 (or 310 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 41.

The square root of 20861897 is about 4567.4825670165. The cubic root of 20861897 is about 275.2863001790.

The spelling of 20861897 in words is "twenty million, eight hundred sixty-one thousand, eight hundred ninety-seven".