20001549631999 has 4 divisors (see below), whose sum is σ = 21540130372936. Its totient is φ = 18462968891064.

The previous prime is 20001549631993. The next prime is 20001549632047. The reversal of 20001549631999 is 99913694510002.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20001549631999 - 2¹³ = 20001549623807 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 (20001549631993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 769290370449 + ... + 769290370474.

It is an arithmetic number, because the mean of its divisors is an integer number (5385032593234).

Almost surely, 2^{20001549631999} is an apocalyptic number.

20001549631999 is a deficient number, since it is larger than the sum of its proper divisors (1538580740937).

20001549631999 is a wasteful number, since it uses less digits than its factorization.

20001549631999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1538580740936.

The product of its (nonzero) digits is 4723920, while the sum is 58.

The spelling of 20001549631999 in words is "twenty trillion, one billion, five hundred forty-nine million, six hundred thirty-one thousand, nine hundred ninety-nine".