402111191 has 4 divisors (see below), whose sum is σ = 402154872. Its totient is φ = 402067512.

The previous prime is 402111173. The next prime is 402111197. The reversal of 402111191 is 191111204.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 402111191 - 2¹⁴ = 402094807 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 (402111197) 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, 2060 + ... + 28433.

It is an arithmetic number, because the mean of its divisors is an integer number (100538718).

Almost surely, 2^402111191 is an apocalyptic number.

402111191 is a deficient number, since it is larger than the sum of its proper divisors (43681).

402111191 is a wasteful number, since it uses less digits than its factorization.

402111191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43680.

The product of its (nonzero) digits is 72, while the sum is 20.

The square root of 402111191 is about 20052.7103155658. The cubic root of 402111191 is about 738.1003081660.

Adding to 402111191 its reverse (191111204), we get a palindrome (593222395).

The spelling of 402111191 in words is "four hundred two million, one hundred eleven thousand, one hundred ninety-one".