468191981 has 4 divisors (see below), whose sum is σ = 468239772. Its totient is φ = 468144192.

The previous prime is 468191947. The next prime is 468191993. The reversal of 468191981 is 189191864.

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 can be written as a sum of positive squares in 2 ways, for example, as 150283081 + 317908900 = 12259^2 + 17830^2 .

It is a cyclic number.

It is not a de Polignac number, because 468191981 - 2¹⁸ = 467929837 is a prime.

It is a super-2 number, since 2×468191981² = 438407462145408722, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (468190981) 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, 3260 + ... + 30773.

It is an arithmetic number, because the mean of its divisors is an integer number (117059943).

Almost surely, 2^468191981 is an apocalyptic number.

It is an amenable number.

468191981 is a deficient number, since it is larger than the sum of its proper divisors (47791).

468191981 is a wasteful number, since it uses less digits than its factorization.

468191981 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47790.

The product of its digits is 124416, while the sum is 47.

The square root of 468191981 is about 21637.7443602608. The cubic root of 468191981 is about 776.4997561304.

The spelling of 468191981 in words is "four hundred sixty-eight million, one hundred ninety-one thousand, nine hundred eighty-one".