661835616 has 96 divisors (see below), whose sum is σ = 1931424768. Its totient is φ = 197061120.

The previous prime is 661835611. The next prime is 661835621. The reversal of 661835616 is 616538166.

It is an interprime number because it is at equal distance from previous prime (661835611) and next prime (661835621).

It is a tau number, because it is divible by the number of its divisors (96).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661835611) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 30135 + ... + 47241.

It is an arithmetic number, because the mean of its divisors is an integer number (20119008).

Almost surely, 2^661835616 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 661835616, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (965712384).

661835616 is an abundant number, since it is smaller than the sum of its proper divisors (1269589152).

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

661835616 is a wasteful number, since it uses less digits than its factorization.

661835616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17164 (or 17156 counting only the distinct ones).

The product of its digits is 155520, while the sum is 42.

The square root of 661835616 is about 25726.1659794070. The cubic root of 661835616 is about 871.4651912383.

The spelling of 661835616 in words is "six hundred sixty-one million, eight hundred thirty-five thousand, six hundred sixteen".