661865053 has 8 divisors (see below), whose sum is σ = 674908416. Its totient is φ = 648925200.

The previous prime is 661865051. The next prime is 661865107. The reversal of 661865053 is 350568166.

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

It is a cyclic number.

It is not a de Polignac number, because 661865053 - 2¹ = 661865051 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 661864997 and 661865015.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661865051) 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, 12901 + ... + 38602.

It is an arithmetic number, because the mean of its divisors is an integer number (84363552).

Almost surely, 2^661865053 is an apocalyptic number.

It is an amenable number.

661865053 is a deficient number, since it is larger than the sum of its proper divisors (13043363).

661865053 is a wasteful number, since it uses less digits than its factorization.

661865053 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51755.

The product of its (nonzero) digits is 129600, while the sum is 40.

The square root of 661865053 is about 25726.7380948304. The cubic root of 661865053 is about 871.4781113350.

The spelling of 661865053 in words is "six hundred sixty-one million, eight hundred sixty-five thousand, fifty-three".