402003644 has 36 divisors (see below), whose sum is σ = 826351344. Its totient is φ = 170606016.

The previous prime is 402003617. The next prime is 402003649. The reversal of 402003644 is 446300204.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (402003649) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10232 + ... + 30144.

It is an arithmetic number, because the mean of its divisors is an integer number (22954204).

Almost surely, 2^402003644 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 402003644, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (413175672).

402003644 is an abundant number, since it is smaller than the sum of its proper divisors (424347700).

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

402003644 is a wasteful number, since it uses less digits than its factorization.

402003644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20034 (or 20025 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 23.

The square root of 402003644 is about 20050.0285286580. The cubic root of 402003644 is about 738.0344992110.

Adding to 402003644 its reverse (446300204), we get a palindrome (848303848).

The spelling of 402003644 in words is "four hundred two million, three thousand, six hundred forty-four".