661015000 has 80 divisors (see below), whose sum is σ = 1570840920. Its totient is φ = 260640000.

The previous prime is 661014973. The next prime is 661015001. The reversal of 661015000 is 510166.

661015000 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661015001) 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, 364095 + ... + 365905.

Almost surely, 2^661015000 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661015000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (785420460).

661015000 is an abundant number, since it is smaller than the sum of its proper divisors (909825920).

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

661015000 is a wasteful number, since it uses less digits than its factorization.

661015000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1910 (or 1891 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 19.

The square root of 661015000 is about 25710.2119789005. The cubic root of 661015000 is about 871.1048630668.

Adding to 661015000 its reverse (510166), we get a palindrome (661525166).

The spelling of 661015000 in words is "six hundred sixty-one million, fifteen thousand".