20897012497 has 4 divisors (see below), whose sum is σ = 21996855280. Its totient is φ = 19797169716.

The previous prime is 20897012491. The next prime is 20897012501. The reversal of 20897012497 is 79421079802.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 79421079802 = 2 ⋅39710539901.

It is a cyclic number.

It is not a de Polignac number, because 20897012497 - 2¹⁵ = 20896979729 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20897012497.

It is not an unprimeable number, because it can be changed into a prime (20897012491) 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, 549921363 + ... + 549921400.

It is an arithmetic number, because the mean of its divisors is an integer number (5499213820).

Almost surely, 2^20897012497 is an apocalyptic number.

It is an amenable number.

20897012497 is a deficient number, since it is larger than the sum of its proper divisors (1099842783).

20897012497 is a wasteful number, since it uses less digits than its factorization.

20897012497 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1099842782.

The product of its (nonzero) digits is 508032, while the sum is 49.

The spelling of 20897012497 in words is "twenty billion, eight hundred ninety-seven million, twelve thousand, four hundred ninety-seven".