212189945 has 16 divisors (see below), whose sum is σ = 278069760. Its totient is φ = 154156800.

The previous prime is 212189941. The next prime is 212189951. The reversal of 212189945 is 549981212.

It is not a de Polignac number, because 212189945 - 2² = 212189941 is a prime.

It is not an unprimeable number, because it can be changed into a prime (212189941) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 80600 + ... + 83190.

It is an arithmetic number, because the mean of its divisors is an integer number (17379360).

Almost surely, 2^212189945 is an apocalyptic number.

It is an amenable number.

212189945 is a deficient number, since it is larger than the sum of its proper divisors (65879815).

212189945 is a wasteful number, since it uses less digits than its factorization.

212189945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4096.

The product of its digits is 51840, while the sum is 41.

The square root of 212189945 is about 14566.7410562555. The cubic root of 212189945 is about 596.4512229812.

It can be divided in two parts, 21 and 2189945, that multiplied together give a triangular number (45988845 = T₉₅₉₀).

The spelling of 212189945 in words is "two hundred twelve million, one hundred eighty-nine thousand, nine hundred forty-five".