661310553 has 8 divisors (see below), whose sum is σ = 884246688. Its totient is φ = 439624064.

The previous prime is 661310549. The next prime is 661310567. The reversal of 661310553 is 355013166.

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 661310553 - 2² = 661310549 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 661310553.

It is not an unprimeable number, because it can be changed into a prime (661310593) 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, 311175 + ... + 313292.

It is an arithmetic number, because the mean of its divisors is an integer number (110530836).

Almost surely, 2^661310553 is an apocalyptic number.

It is an amenable number.

661310553 is a deficient number, since it is larger than the sum of its proper divisors (222936135).

661310553 is a wasteful number, since it uses less digits than its factorization.

661310553 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 624823.

The product of its (nonzero) digits is 8100, while the sum is 30.

The square root of 661310553 is about 25715.9591110268. The cubic root of 661310553 is about 871.2346731789.

The spelling of 661310553 in words is "six hundred sixty-one million, three hundred ten thousand, five hundred fifty-three".