661551123085 has 8 divisors (see below), whose sum is σ = 795186662400. Its totient is φ = 528357355344.

The previous prime is 661551123073. The next prime is 661551123089. The reversal of 661551123085 is 580321155166.

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 661551123085 - 2⁷ = 661551122957 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661551123089) 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, 110439597 + ... + 110445586.

It is an arithmetic number, because the mean of its divisors is an integer number (99398332800).

Almost surely, 2^661551123085 is an apocalyptic number.

It is an amenable number.

661551123085 is a deficient number, since it is larger than the sum of its proper divisors (133635539315).

661551123085 is a wasteful number, since it uses less digits than its factorization.

661551123085 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 220885787.

The product of its (nonzero) digits is 216000, while the sum is 43.

The spelling of 661551123085 in words is "six hundred sixty-one billion, five hundred fifty-one million, one hundred twenty-three thousand, eighty-five".