401191831 has 4 divisors (see below), whose sum is σ = 404872600. Its totient is φ = 397511064.

The previous prime is 401191807. The next prime is 401191873. The reversal of 401191831 is 138191104.

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

It is a cyclic number.

It is not a de Polignac number, because 401191831 - 2¹⁵ = 401159063 is a prime.

It is a super-2 number, since 2×401191831² = 321909770522265122, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 401191831.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (401191031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1840221 + ... + 1840438.

It is an arithmetic number, because the mean of its divisors is an integer number (101218150).

Almost surely, 2^401191831 is an apocalyptic number.

401191831 is a deficient number, since it is larger than the sum of its proper divisors (3680769).

401191831 is a wasteful number, since it uses less digits than its factorization.

401191831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3680768.

The product of its (nonzero) digits is 864, while the sum is 28.

The square root of 401191831 is about 20029.7736132988. The cubic root of 401191831 is about 737.5373646108.

The spelling of 401191831 in words is "four hundred one million, one hundred ninety-one thousand, eight hundred thirty-one".