16661240 has 16 divisors (see below), whose sum is σ = 37487880. Its totient is φ = 6664480.

The previous prime is 16661237. The next prime is 16661243. The reversal of 16661240 is 4216661.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (16661237) and next prime (16661243).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16661243) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 208226 + ... + 208305.

Almost surely, 2^16661240 is an apocalyptic number.

16661240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

16661240 is an abundant number, since it is smaller than the sum of its proper divisors (20826640).

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

16661240 is a wasteful number, since it uses less digits than its factorization.

16661240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 416542 (or 416538 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 26.

The square root of 16661240 is about 4081.8182223122. The cubic root of 16661240 is about 255.4087510827.

The spelling of 16661240 in words is "sixteen million, six hundred sixty-one thousand, two hundred forty".