1661412213 has 24 divisors (see below), whose sum is σ = 2418515736. Its totient is φ = 1099008000.

The previous prime is 1661412187. The next prime is 1661412229. The reversal of 1661412213 is 3122141661.

It is a happy number.

1661412213 is a `hidden beast` number, since 16 + 614 + 1 + 22 + 13 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 432348849 + 1229063364 = 20793^2 + 35058^2 .

It is not a de Polignac number, because 1661412213 - 2⁸ = 1661411957 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1661412293) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 978181 + ... + 979877.

It is an arithmetic number, because the mean of its divisors is an integer number (100771489).

Almost surely, 2^1661412213 is an apocalyptic number.

It is an amenable number.

1661412213 is a deficient number, since it is larger than the sum of its proper divisors (757103523).

1661412213 is a wasteful number, since it uses less digits than its factorization.

1661412213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2485 (or 2482 counting only the distinct ones).

The product of its digits is 1728, while the sum is 27.

The square root of 1661412213 is about 40760.4245929799. The cubic root of 1661412213 is about 1184.3838210838.

Adding to 1661412213 its reverse (3122141661), we get a palindrome (4783553874).

The spelling of 1661412213 in words is "one billion, six hundred sixty-one million, four hundred twelve thousand, two hundred thirteen".