661561202 has 16 divisors (see below), whose sum is σ = 998373600. Its totient is φ = 328776000.

The previous prime is 661561163. The next prime is 661561217. The reversal of 661561202 is 202165166.

It is an unprimeable number.

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, 309674 + ... + 311802.

It is an arithmetic number, because the mean of its divisors is an integer number (62398350).

Almost surely, 2^661561202 is an apocalyptic number.

661561202 is a deficient number, since it is larger than the sum of its proper divisors (336812398).

661561202 is a wasteful number, since it uses less digits than its factorization.

661561202 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3001.

The product of its (nonzero) digits is 4320, while the sum is 29.

The square root of 661561202 is about 25720.8320627463. The cubic root of 661561202 is about 871.3447306575.

The spelling of 661561202 in words is "six hundred sixty-one million, five hundred sixty-one thousand, two hundred two".