181961516 has 24 divisors (see below), whose sum is σ = 347820480. Its totient is φ = 82605200.

The previous prime is 181961513. The next prime is 181961531. The reversal of 181961516 is 615169181.

It is a self number, because there is not a number n which added to its sum of digits gives 181961516.

It is not an unprimeable number, because it can be changed into a prime (181961513) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 40595 + ... + 44853.

It is an arithmetic number, because the mean of its divisors is an integer number (14492520).

Almost surely, 2^181961516 is an apocalyptic number.

It is an amenable number.

181961516 is a deficient number, since it is larger than the sum of its proper divisors (165858964).

181961516 is a wasteful number, since it uses less digits than its factorization.

181961516 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5245 (or 5243 counting only the distinct ones).

The product of its digits is 12960, while the sum is 38.

The square root of 181961516 is about 13489.3111758903. The cubic root of 181961516 is about 566.6651646250.

The spelling of 181961516 in words is "one hundred eighty-one million, nine hundred sixty-one thousand, five hundred sixteen".