661612545 has 48 divisors (see below), whose sum is σ = 1324657152. Its totient is φ = 301908480.

The previous prime is 661612543. The next prime is 661612559. The reversal of 661612545 is 545216166.

It is not a de Polignac number, because 661612545 - 2¹ = 661612543 is a prime.

It is not an unprimeable number, because it can be changed into a prime (661612541) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 30897 + ... + 47726.

It is an arithmetic number, because the mean of its divisors is an integer number (27597024).

Almost surely, 2^661612545 is an apocalyptic number.

It is an amenable number.

661612545 is an abundant number, since it is smaller than the sum of its proper divisors (663044607).

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

661612545 is a wasteful number, since it uses less digits than its factorization.

661612545 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78662 (or 78659 counting only the distinct ones).

The product of its digits is 43200, while the sum is 36.

The square root of 661612545 is about 25721.8301254013. The cubic root of 661612545 is about 871.3672714267.

The spelling of 661612545 in words is "six hundred sixty-one million, six hundred twelve thousand, five hundred forty-five".