21920985449 has 12 divisors (see below), whose sum is σ = 24099121200. Its totient is φ = 19924733400.

The previous prime is 21920985433. The next prime is 21920985469. The reversal of 21920985449 is 94458902912.

It is not a de Polignac number, because 21920985449 - 2⁴ = 21920985433 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21920985449.

It is not an unprimeable number, because it can be changed into a prime (21920985469) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 919814 + ... + 943344.

It is an arithmetic number, because the mean of its divisors is an integer number (2008260100).

Almost surely, 2^21920985449 is an apocalyptic number.

It is an amenable number.

21920985449 is a deficient number, since it is larger than the sum of its proper divisors (2178135751).

21920985449 is a wasteful number, since it uses less digits than its factorization.

21920985449 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31252 (or 31241 counting only the distinct ones).

The product of its (nonzero) digits is 1866240, while the sum is 53.

The spelling of 21920985449 in words is "twenty-one billion, nine hundred twenty million, nine hundred eighty-five thousand, four hundred forty-nine".