661489416 has 240 divisors, whose sum is σ = 2189935440. Its totient is φ = 185976000.

The previous prime is 661489403. The next prime is 661489417. The reversal of 661489416 is 614984166.

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (661489417) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 2635291 + ... + 2635541.

It is an arithmetic number, because the mean of its divisors is an integer number (9124731).

Almost surely, 2^661489416 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 661489416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1094967720).

661489416 is an abundant number, since it is smaller than the sum of its proper divisors (1528446024).

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

661489416 is a wasteful number, since it uses less digits than its factorization.

661489416 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 366 (or 346 counting only the distinct ones).

The product of its digits is 248832, while the sum is 45.

The square root of 661489416 is about 25719.4365412619. The cubic root of 661489416 is about 871.3132129812.

The spelling of 661489416 in words is "six hundred sixty-one million, four hundred eighty-nine thousand, four hundred sixteen".