661849987476 has 96 divisors (see below), whose sum is σ = 1666261352448. Its totient is φ = 203871444480.

The previous prime is 661849987441. The next prime is 661849987481. The reversal of 661849987476 is 674789948166.

It is a junction number, because it is equal to n+sod(n) for n = 661849987398 and 661849987407.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5008485 + ... + 5138931.

It is an arithmetic number, because the mean of its divisors is an integer number (17356889088).

Almost surely, 2^661849987476 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661849987476, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (833130676224).

661849987476 is an abundant number, since it is smaller than the sum of its proper divisors (1004411364972).

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

661849987476 is a wasteful number, since it uses less digits than its factorization.

661849987476 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 131101 (or 131099 counting only the distinct ones).

The product of its digits is 877879296, while the sum is 75.

The spelling of 661849987476 in words is "six hundred sixty-one billion, eight hundred forty-nine million, nine hundred eighty-seven thousand, four hundred seventy-six".