20897901 has 6 divisors (see below), whose sum is σ = 30185870. Its totient is φ = 13931928.

The previous prime is 20897873. The next prime is 20897909. The reversal of 20897901 is 10979802.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 12638025 + 8259876 = 3555^2 + 2874^2 .

It is not a de Polignac number, because 20897901 - 2¹³ = 20889709 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20897909) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1160986 + ... + 1161003.

Almost surely, 2^20897901 is an apocalyptic number.

It is an amenable number.

20897901 is a deficient number, since it is larger than the sum of its proper divisors (9287969).

20897901 is a wasteful number, since it uses less digits than its factorization.

20897901 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2321995 (or 2321992 counting only the distinct ones).

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

The square root of 20897901 is about 4571.4222075849. The cubic root of 20897901 is about 275.4445745619. Note that the first 3 decimals are identical.

The spelling of 20897901 in words is "twenty million, eight hundred ninety-seven thousand, nine hundred one".