20121220999 has 8 divisors (see below), whose sum is σ = 22029669648. Its totient is φ = 18225980160.

The previous prime is 20121220981. The next prime is 20121221033. The reversal of 20121220999 is 99902212102.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20121220999 - 2¹³ = 20121212807 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 (20121220949) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3298762 + ... + 3304855.

It is an arithmetic number, because the mean of its divisors is an integer number (2753708706).

Almost surely, 2^20121220999 is an apocalyptic number.

20121220999 is a deficient number, since it is larger than the sum of its proper divisors (1908448649).

20121220999 is a wasteful number, since it uses less digits than its factorization.

20121220999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6603905.

The product of its (nonzero) digits is 11664, while the sum is 37.

The spelling of 20121220999 in words is "twenty billion, one hundred twenty-one million, two hundred twenty thousand, nine hundred ninety-nine".