181920212 has 12 divisors (see below), whose sum is σ = 335116320. Its totient is φ = 86172696.

The previous prime is 181920203. The next prime is 181920251. The reversal of 181920212 is 212029181.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1196768 + ... + 1196919.

It is an arithmetic number, because the mean of its divisors is an integer number (27926360).

Almost surely, 2^181920212 is an apocalyptic number.

It is an amenable number.

181920212 is a deficient number, since it is larger than the sum of its proper divisors (153196108).

181920212 is a wasteful number, since it uses less digits than its factorization.

181920212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2393710 (or 2393708 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 26.

The square root of 181920212 is about 13487.7800990378. The cubic root of 181920212 is about 566.6222850285.

Adding to 181920212 its reverse (212029181), we get a palindrome (393949393).

The spelling of 181920212 in words is "one hundred eighty-one million, nine hundred twenty thousand, two hundred twelve".