661162540 has 12 divisors (see below), whose sum is σ = 1388441376. Its totient is φ = 264465008.

The previous prime is 661162529. The next prime is 661162543. The reversal of 661162540 is 45261166.

It is not an unprimeable number, because it can be changed into a prime (661162543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16529044 + ... + 16529083.

It is an arithmetic number, because the mean of its divisors is an integer number (115703448).

Almost surely, 2^661162540 is an apocalyptic number.

It is an amenable number.

661162540 is an abundant number, since it is smaller than the sum of its proper divisors (727278836).

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

661162540 is a wasteful number, since it uses less digits than its factorization.

661162540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33058136 (or 33058134 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 661162540 is about 25713.0811067052. The cubic root of 661162540 is about 871.1696690851.

The spelling of 661162540 in words is "six hundred sixty-one million, one hundred sixty-two thousand, five hundred forty".