661031610100 has 36 divisors (see below), whose sum is σ = 1435191204384. Its totient is φ = 264273914080.

The previous prime is 661031610059. The next prime is 661031610119. The reversal of 661031610100 is 1016130166.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1542472 + ... + 1923871.

It is an arithmetic number, because the mean of its divisors is an integer number (39866422344).

Almost surely, 2^661031610100 is an apocalyptic number.

It is an amenable number.

661031610100 is an abundant number, since it is smaller than the sum of its proper divisors (774159594284).

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

661031610100 is a wasteful number, since it uses less digits than its factorization.

661031610100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3468264 (or 3468257 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 25.

Adding to 661031610100 its reverse (1016130166), we get a palindrome (662047740266).

The spelling of 661031610100 in words is "six hundred sixty-one billion, thirty-one million, six hundred ten thousand, one hundred".