21998539013 has 4 divisors (see below), whose sum is σ = 23998406208. Its totient is φ = 19998671820.

The previous prime is 21998539009. The next prime is 21998539117. The reversal of 21998539013 is 31093589912.

It is a happy number.

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 21998539013 - 2² = 21998539009 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 (21998529013) 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, 999933581 + ... + 999933602.

It is an arithmetic number, because the mean of its divisors is an integer number (5999601552).

Almost surely, 2^21998539013 is an apocalyptic number.

It is an amenable number.

21998539013 is a deficient number, since it is larger than the sum of its proper divisors (1999867195).

21998539013 is a wasteful number, since it uses less digits than its factorization.

21998539013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1999867194.

The product of its (nonzero) digits is 524880, while the sum is 50.

The spelling of 21998539013 in words is "twenty-one billion, nine hundred ninety-eight million, five hundred thirty-nine thousand, thirteen".