20115142209 has 12 divisors (see below), whose sum is σ = 30131324496. Its totient is φ = 13410094644.

The previous prime is 20115142199. The next prime is 20115142211. The reversal of 20115142209 is 90224151102.

It is not a de Polignac number, because 20115142209 - 2²⁸ = 19846706753 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (20115142219) 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, 41388939 + ... + 41389424.

It is an arithmetic number, because the mean of its divisors is an integer number (2510943708).

Almost surely, 2^20115142209 is an apocalyptic number.

It is an amenable number.

20115142209 is a deficient number, since it is larger than the sum of its proper divisors (10016182287).

20115142209 is an frugal number, since it uses more digits than its factorization.

20115142209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 82778378 (or 82778366 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 27.

The spelling of 20115142209 in words is "twenty billion, one hundred fifteen million, one hundred forty-two thousand, two hundred nine".