40099644 has 72 divisors (see below), whose sum is σ = 112625520. Its totient is φ = 12338352.

The previous prime is 40099643. The next prime is 40099669. The reversal of 40099644 is 44699004.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

40099644 is a `hidden beast` number, since 4 + 0 + 0 + 9 + 9 + 644 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nialpdrome in base 13.

It is a junction number, because it is equal to n+sod(n) for n = 40099599 and 40099608.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40099643) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3084582 + ... + 3084594.

Almost surely, 2^40099644 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 40099644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (56312760).

40099644 is an abundant number, since it is smaller than the sum of its proper divisors (72525876).

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

40099644 is an frugal number, since it uses more digits than its factorization.

40099644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78 (or 18 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The square root of 40099644 is about 6332.4279703760. The cubic root of 40099644 is about 342.2789352578.

The spelling of 40099644 in words is "forty million, ninety-nine thousand, six hundred forty-four".