20001210109391 has 16 divisors (see below), whose sum is σ = 23013298152000. Its totient is φ = 17027828740608.

The previous prime is 20001210109339. The next prime is 20001210109393. The reversal of 20001210109391 is 19390101210002.

It is a de Polignac number, because none of the positive numbers 2^k-20001210109391 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 (20001210109393) 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, 17370311 + ... + 18485943.

It is an arithmetic number, because the mean of its divisors is an integer number (1438331134500).

Almost surely, 2^{20001210109391} is an apocalyptic number.

20001210109391 is a deficient number, since it is larger than the sum of its proper divisors (3012088042609).

20001210109391 is a wasteful number, since it uses less digits than its factorization.

20001210109391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1132978.

The product of its (nonzero) digits is 972, while the sum is 29.

Adding to 20001210109391 its reverse (19390101210002), we get a palindrome (39391311319393).

The spelling of 20001210109391 in words is "twenty trillion, one billion, two hundred ten million, one hundred nine thousand, three hundred ninety-one".