20981897599 has 16 divisors (see below), whose sum is σ = 22680723744. Its totient is φ = 19295337600.

The previous prime is 20981897551. The next prime is 20981897647. The reversal of 20981897599 is 99579818902.

It is an interprime number because it is at equal distance from previous prime (20981897551) and next prime (20981897647).

It is a cyclic number.

It is not a de Polignac number, because 20981897599 - 2¹³ = 20981889407 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 (20981897549) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 4216677 + ... + 4221649.

It is an arithmetic number, because the mean of its divisors is an integer number (1417545234).

Almost surely, 2^20981897599 is an apocalyptic number.

20981897599 is a deficient number, since it is larger than the sum of its proper divisors (1698826145).

20981897599 is a wasteful number, since it uses less digits than its factorization.

20981897599 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6138.

The product of its (nonzero) digits is 29393280, while the sum is 67.

The spelling of 20981897599 in words is "twenty billion, nine hundred eighty-one million, eight hundred ninety-seven thousand, five hundred ninety-nine".