20818813969 has 4 divisors (see below), whose sum is σ = 21914541040. Its totient is φ = 19723086900.

The previous prime is 20818813957. The next prime is 20818813979. The reversal of 20818813969 is 96931881802.

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.

It is a cyclic number.

It is not a de Polignac number, because 20818813969 - 2¹⁵ = 20818781201 is a prime.

It is a super-2 number, since 2×20818813969² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20818813919) 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, 547863507 + ... + 547863544.

It is an arithmetic number, because the mean of its divisors is an integer number (5478635260).

Almost surely, 2^20818813969 is an apocalyptic number.

It is an amenable number.

20818813969 is a deficient number, since it is larger than the sum of its proper divisors (1095727071).

20818813969 is a wasteful number, since it uses less digits than its factorization.

20818813969 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1095727070.

The product of its (nonzero) digits is 1492992, while the sum is 55.

The spelling of 20818813969 in words is "twenty billion, eight hundred eighteen million, eight hundred thirteen thousand, nine hundred sixty-nine".