661107216 has 360 divisors, whose sum is σ = 2301227712. Its totient is φ = 162624000.

The previous prime is 661107211. The next prime is 661107233. The reversal of 661107216 is 612701166.

It is not an unprimeable number, because it can be changed into a prime (661107211) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 6545566 + ... + 6545666.

Almost surely, 2^661107216 is an apocalyptic number.

661107216 is a gapful number since it is divisible by the number (66) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 661107216, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1150613856).

661107216 is an abundant number, since it is smaller than the sum of its proper divisors (1640120496).

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

661107216 is a wasteful number, since it uses less digits than its factorization.

661107216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 171 (or 147 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 30.

The square root of 661107216 is about 25712.0052893585. The cubic root of 661107216 is about 871.1453694955.

The spelling of 661107216 in words is "six hundred sixty-one million, one hundred seven thousand, two hundred sixteen".