661542828 has 48 divisors (see below), whose sum is σ = 1636225920. Its totient is φ = 207311104.

The previous prime is 661542797. The next prime is 661542841. The reversal of 661542828 is 828245166.

It is a self number, because there is not a number n which added to its sum of digits gives 661542828.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 329275 + ... + 331277.

It is an arithmetic number, because the mean of its divisors is an integer number (34088040).

Almost surely, 2^661542828 is an apocalyptic number.

661542828 is a gapful number since it is divisible by the number (68) formed by its first and last digit.

It is an amenable number.

661542828 is an abundant number, since it is smaller than the sum of its proper divisors (974683092).

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

661542828 is a wasteful number, since it uses less digits than its factorization.

661542828 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3646 (or 3644 counting only the distinct ones).

The product of its digits is 184320, while the sum is 42.

The square root of 661542828 is about 25720.4748789753. The cubic root of 661542828 is about 871.3366637614.

The spelling of 661542828 in words is "six hundred sixty-one million, five hundred forty-two thousand, eight hundred twenty-eight".