661016221612 has 12 divisors (see below), whose sum is σ = 1157315689656. Its totient is φ = 330354596000.

The previous prime is 661016221571. The next prime is 661016221643. The reversal of 661016221612 is 216122610166.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 38369014 + ... + 38386237.

It is an arithmetic number, because the mean of its divisors is an integer number (96442974138).

Almost surely, 2^661016221612 is an apocalyptic number.

It is an amenable number.

661016221612 is a deficient number, since it is larger than the sum of its proper divisors (496299468044).

661016221612 is a wasteful number, since it uses less digits than its factorization.

661016221612 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76757408 (or 76757406 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 34.

Adding to 661016221612 its reverse (216122610166), we get a palindrome (877138831778).

The spelling of 661016221612 in words is "six hundred sixty-one billion, sixteen million, two hundred twenty-one thousand, six hundred twelve".