20901897 has 12 divisors (see below), whose sum is σ = 30347460. Its totient is φ = 13862688.

The previous prime is 20901889. The next prime is 20901901. The reversal of 20901897 is 79810902.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 10732176 + 10169721 = 3276^2 + 3189^2 .

It is not a de Polignac number, because 20901897 - 2³ = 20901889 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20901817) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4122 + ... + 7667.

It is an arithmetic number, because the mean of its divisors is an integer number (2528955).

Almost surely, 2^20901897 is an apocalyptic number.

It is an amenable number.

20901897 is a deficient number, since it is larger than the sum of its proper divisors (9445563).

20901897 is a wasteful number, since it uses less digits than its factorization.

20901897 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11992 (or 11989 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 36.

The square root of 20901897 is about 4571.8592498020. The cubic root of 20901897 is about 275.4621298557.

The spelling of 20901897 in words is "twenty million, nine hundred one thousand, eight hundred ninety-seven".