661045212 has 30 divisors (see below), whose sum is σ = 1728103608. Its totient is φ = 220348296.

The previous prime is 661045201. The next prime is 661045213. The reversal of 661045212 is 212540166.

661045212 is a `hidden beast` number, since 6 + 610 + 45 + 2 + 1 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661045213) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 1019808 + ... + 1020455.

Almost surely, 2^661045212 is an apocalyptic number.

It is an amenable number.

661045212 is an abundant number, since it is smaller than the sum of its proper divisors (1067058396).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

661045212 is a wasteful number, since it uses less digits than its factorization.

661045212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2040279 (or 2040268 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The square root of 661045212 is about 25710.7995208239. The cubic root of 661045212 is about 871.1181342831.

Adding to 661045212 its reverse (212540166), we get a palindrome (873585378).

The spelling of 661045212 in words is "six hundred sixty-one million, forty-five thousand, two hundred twelve".