20091891893 has 4 divisors (see below), whose sum is σ = 20097582348. Its totient is φ = 20086201440.

The previous prime is 20091891877. The next prime is 20091891913. The reversal of 20091891893 is 39819819002.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 6309601489 + 13782290404 = 79433^2 + 117398^2 .

It is a cyclic number.

It is not a de Polignac number, because 20091891893 - 2⁴ = 20091891877 is a prime.

It is a super-3 number, since 3×20091891893³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20091891823) 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, 2839928 + ... + 2846993.

It is an arithmetic number, because the mean of its divisors is an integer number (5024395587).

Almost surely, 2^20091891893 is an apocalyptic number.

It is an amenable number.

20091891893 is a deficient number, since it is larger than the sum of its proper divisors (5690455).

20091891893 is an equidigital number, since it uses as much as digits as its factorization.

20091891893 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5690454.

The product of its (nonzero) digits is 279936, while the sum is 50.

The spelling of 20091891893 in words is "twenty billion, ninety-one million, eight hundred ninety-one thousand, eight hundred ninety-three".