661225210 has 16 divisors (see below), whose sum is σ = 1191034656. Its totient is φ = 264305808.

The previous prime is 661225153. The next prime is 661225219. The reversal of 661225210 is 12522166.

It is not an unprimeable number, because it can be changed into a prime (661225219) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7464 + ... + 37123.

It is an arithmetic number, because the mean of its divisors is an integer number (74439666).

Almost surely, 2^661225210 is an apocalyptic number.

661225210 is a deficient number, since it is larger than the sum of its proper divisors (529809446).

661225210 is a wasteful number, since it uses less digits than its factorization.

661225210 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 46077.

The product of its (nonzero) digits is 1440, while the sum is 25.

The square root of 661225210 is about 25714.2997182502. The cubic root of 661225210 is about 871.1971935716.

Adding to 661225210 its reverse (12522166), we get a palindrome (673747376).

The spelling of 661225210 in words is "six hundred sixty-one million, two hundred twenty-five thousand, two hundred ten".