181964947 has 4 divisors (see below), whose sum is σ = 187834816. Its totient is φ = 176095080.

The previous prime is 181964941. The next prime is 181964963. The reversal of 181964947 is 749469181.

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 181964947 - 2¹⁹ = 181440659 is a prime.

It is a super-2 number, since 2×181964947² = 66222483873425618, 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 181964947.

It is not an unprimeable number, because it can be changed into a prime (181964941) 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, 2934888 + ... + 2934949.

It is an arithmetic number, because the mean of its divisors is an integer number (46958704).

Almost surely, 2^181964947 is an apocalyptic number.

181964947 is a deficient number, since it is larger than the sum of its proper divisors (5869869).

181964947 is an equidigital number, since it uses as much as digits as its factorization.

181964947 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5869868.

The product of its digits is 435456, while the sum is 49.

The square root of 181964947 is about 13489.4383500574. The cubic root of 181964947 is about 566.6687262132.

It can be divided in two parts, 1819 and 64947, that added together give a palindrome (66766).

The spelling of 181964947 in words is "one hundred eighty-one million, nine hundred sixty-four thousand, nine hundred forty-seven".