661761930 has 16 divisors (see below), whose sum is σ = 1588228704. Its totient is φ = 176469840.

The previous prime is 661761917. The next prime is 661761931. The reversal of 661761930 is 39167166.

It is not an unprimeable number, because it can be changed into a prime (661761931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11029336 + ... + 11029395.

It is an arithmetic number, because the mean of its divisors is an integer number (99264294).

Almost surely, 2^661761930 is an apocalyptic number.

661761930 is an abundant number, since it is smaller than the sum of its proper divisors (926466774).

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

661761930 is a wasteful number, since it uses less digits than its factorization.

661761930 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22058741.

The product of its (nonzero) digits is 40824, while the sum is 39.

The square root of 661761930 is about 25724.7338178649. The cubic root of 661761930 is about 871.4328482789.

The spelling of 661761930 in words is "six hundred sixty-one million, seven hundred sixty-one thousand, nine hundred thirty".