661563130 has 16 divisors (see below), whose sum is σ = 1202605704. Its totient is φ = 262004800.

The previous prime is 661563113. The next prime is 661563137. The reversal of 661563130 is 31365166.

It can be written as a sum of positive squares in 4 ways, for example, as 659411041 + 2152089 = 25679^2 + 1467^2 .

It is a junction number, because it is equal to n+sod(n) for n = 661563092 and 661563101.

It is not an unprimeable number, because it can be changed into a prime (661563137) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 326497 + ... + 328516.

Almost surely, 2^661563130 is an apocalyptic number.

661563130 is a deficient number, since it is larger than the sum of its proper divisors (541042574).

661563130 is a wasteful number, since it uses less digits than its factorization.

661563130 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 655121.

The product of its (nonzero) digits is 9720, while the sum is 31.

The square root of 661563130 is about 25720.8695420664. The cubic root of 661563130 is about 871.3455771153.

The spelling of 661563130 in words is "six hundred sixty-one million, five hundred sixty-three thousand, one hundred thirty".