402002644 has 6 divisors (see below), whose sum is σ = 703504634. Its totient is φ = 201001320.

The previous prime is 402002641. The next prime is 402002651. The reversal of 402002644 is 446200204.

It can be written as a sum of positive squares in only one way, i.e., 402002500 + 144 = 20050^2 + 12^2 .

It is a super-2 number, since 2×402002644² = 323212251565981472, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (402002641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 50250327 + ... + 50250334.

Almost surely, 2^402002644 is an apocalyptic number.

It is an amenable number.

402002644 is a deficient number, since it is larger than the sum of its proper divisors (301501990).

402002644 is a wasteful number, since it uses less digits than its factorization.

402002644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 100500665 (or 100500663 counting only the distinct ones).

The product of its (nonzero) digits is 1536, while the sum is 22.

The square root of 402002644 is about 20050.0035910221. The cubic root of 402002644 is about 738.0338872472.

Adding to 402002644 its reverse (446200204), we get a palindrome (848202848).

The spelling of 402002644 in words is "four hundred two million, two thousand, six hundred forty-four".