20897453285 has 4 divisors (see below), whose sum is σ = 25076943948. Its totient is φ = 16717962624.

The previous prime is 20897453281. The next prime is 20897453287. The reversal of 20897453285 is 58235479802.

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

It can be written as a sum of positive squares in 2 ways, for example, as 3969882049 + 16927571236 = 63007^2 + 130106^2 .

It is a cyclic number.

It is not a de Polignac number, because 20897453285 - 2² = 20897453281 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 (20897453281) 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, 2089745324 + ... + 2089745333.

It is an arithmetic number, because the mean of its divisors is an integer number (6269235987).

Almost surely, 2^20897453285 is an apocalyptic number.

It is an amenable number.

20897453285 is a deficient number, since it is larger than the sum of its proper divisors (4179490663).

20897453285 is an equidigital number, since it uses as much as digits as its factorization.

20897453285 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4179490662.

The product of its (nonzero) digits is 4838400, while the sum is 53.

The spelling of 20897453285 in words is "twenty billion, eight hundred ninety-seven million, four hundred fifty-three thousand, two hundred eighty-five".