16442640 has 120 divisors (see below), whose sum is σ = 56668248. Its totient is φ = 4270080.

The previous prime is 16442609. The next prime is 16442659. The reversal of 16442640 is 4624461.

16442640 is a `hidden beast` number, since 16 + 4 + 4 + 2 + 640 = 666.

16442640 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 4 ways, for example, as 665856 + 15776784 = 816^2 + 3972^2 .

It is a tau number, because it is divible by the number of its divisors (120).

It is a super-3 number, since 3×16442640³ (a number of 23 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 29242 + ... + 29798.

Almost surely, 2^16442640 is an apocalyptic number.

16442640 is a gapful number since it is divisible by the number (10) 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 16442640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28334124).

16442640 is an abundant number, since it is smaller than the sum of its proper divisors (40225608).

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

16442640 is a wasteful number, since it uses less digits than its factorization.

16442640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 617 (or 608 counting only the distinct ones).

The product of its (nonzero) digits is 4608, while the sum is 27.

The square root of 16442640 is about 4054.9525274656. The cubic root of 16442640 is about 254.2868192400.

The spelling of 16442640 in words is "sixteen million, four hundred forty-two thousand, six hundred forty".