661200081 has 8 divisors (see below), whose sum is σ = 882051744. Its totient is φ = 440574240.

The previous prime is 661200077. The next prime is 661200103. The reversal of 661200081 is 180002166.

661200081 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 661200081 - 2² = 661200077 is a prime.

It is a super-2 number, since 2×661200081² = 874371094228813122, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (661200011) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 49500 + ... + 61421.

It is an arithmetic number, because the mean of its divisors is an integer number (110256468).

Almost surely, 2^661200081 is an apocalyptic number.

It is an amenable number.

661200081 is a deficient number, since it is larger than the sum of its proper divisors (220851663).

661200081 is a wasteful number, since it uses less digits than its factorization.

661200081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 112911.

The product of its (nonzero) digits is 576, while the sum is 24.

The square root of 661200081 is about 25713.8110944294. The cubic root of 661200081 is about 871.1861571948.

The spelling of 661200081 in words is "six hundred sixty-one million, two hundred thousand, eighty-one".