661412790 has 40 divisors (see below), whose sum is σ = 1778467680. Its totient is φ = 176376528.

The previous prime is 661412789. The next prime is 661412797. The reversal of 661412790 is 97214166.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661412797) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 407470 + ... + 409089.

It is an arithmetic number, because the mean of its divisors is an integer number (44461692).

Almost surely, 2^661412790 is an apocalyptic number.

661412790 is an abundant number, since it is smaller than the sum of its proper divisors (1117054890).

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

661412790 is a wasteful number, since it uses less digits than its factorization.

661412790 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 816578 (or 816569 counting only the distinct ones).

The product of its (nonzero) digits is 18144, while the sum is 36.

The square root of 661412790 is about 25717.9468465117. The cubic root of 661412790 is about 871.2795677845.

The spelling of 661412790 in words is "six hundred sixty-one million, four hundred twelve thousand, seven hundred ninety".