661005100028 has 24 divisors (see below), whose sum is σ = 1423703293152. Its totient is φ = 261496522944.

The previous prime is 661005099983. The next prime is 661005100061. The reversal of 661005100028 is 820001500166.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 907973675 + ... + 907974402.

It is an arithmetic number, because the mean of its divisors is an integer number (59320970548).

Almost surely, 2^661005100028 is an apocalyptic number.

It is an amenable number.

661005100028 is an abundant number, since it is smaller than the sum of its proper divisors (762698193124).

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

661005100028 is a wasteful number, since it uses less digits than its factorization.

661005100028 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1815948101 (or 1815948099 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 29.

The spelling of 661005100028 in words is "six hundred sixty-one billion, five million, one hundred thousand, twenty-eight".