402006641 has 4 divisors (see below), whose sum is σ = 402122484. Its totient is φ = 401890800.

The previous prime is 402006629. The next prime is 402006659. The reversal of 402006641 is 146600204.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 388287025 + 13719616 = 19705^2 + 3704^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-402006641 is a prime.

It is a Duffinian 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 in 3 ways as a sum of consecutive naturals, for example, 52550 + ... + 59711.

It is an arithmetic number, because the mean of its divisors is an integer number (100530621).

Almost surely, 2^402006641 is an apocalyptic number.

It is an amenable number.

402006641 is a deficient number, since it is larger than the sum of its proper divisors (115843).

402006641 is a wasteful number, since it uses less digits than its factorization.

402006641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115842.

The product of its (nonzero) digits is 1152, while the sum is 23.

The square root of 402006641 is about 20050.1032665670. The cubic root of 402006641 is about 738.0363332606.

Adding to 402006641 its reverse (146600204), we get a palindrome (548606845).

The spelling of 402006641 in words is "four hundred two million, six thousand, six hundred forty-one".