661028499 has 16 divisors (see below), whose sum is σ = 993920640. Its totient is φ = 434107080.

The previous prime is 661028497. The next prime is 661028549. The reversal of 661028499 is 994820166.

It is a happy number.

661028499 is a `hidden beast` number, since 6 + 610 + 28 + 4 + 9 + 9 = 666.

It is not a de Polignac number, because 661028499 - 2¹ = 661028497 is a prime.

It is not an unprimeable number, because it can be changed into a prime (661028497) 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, 180897 + ... + 184514.

It is an arithmetic number, because the mean of its divisors is an integer number (62120040).

Almost surely, 2^661028499 is an apocalyptic number.

661028499 is a deficient number, since it is larger than the sum of its proper divisors (332892141).

661028499 is a wasteful number, since it uses less digits than its factorization.

661028499 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 365487 (or 365481 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 45.

The square root of 661028499 is about 25710.4744997054. The cubic root of 661028499 is about 871.1107928185.

The spelling of 661028499 in words is "six hundred sixty-one million, twenty-eight thousand, four hundred ninety-nine".