661547061 has 64 divisors (see below), whose sum is σ = 1198080000. Its totient is φ = 352159488.

The previous prime is 661547059. The next prime is 661547069. The reversal of 661547061 is 160745166.

It is not a de Polignac number, because 661547061 - 2¹ = 661547059 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661547069) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 329940 + ... + 331938.

It is an arithmetic number, because the mean of its divisors is an integer number (18720000).

Almost surely, 2^661547061 is an apocalyptic number.

It is an amenable number.

661547061 is a deficient number, since it is larger than the sum of its proper divisors (536532939).

661547061 is a wasteful number, since it uses less digits than its factorization.

661547061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2135 (or 2129 counting only the distinct ones).

The product of its (nonzero) digits is 30240, while the sum is 36.

The square root of 661547061 is about 25720.5571673710. The cubic root of 661547061 is about 871.3385222253.

The spelling of 661547061 in words is "six hundred sixty-one million, five hundred forty-seven thousand, sixty-one".