402021541 has 2 divisors, whose sum is σ = 402021542. Its totient is φ = 402021540.

The previous prime is 402021527. The next prime is 402021611. The reversal of 402021541 is 145120204.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 269288100 + 132733441 = 16410^2 + 11521^2 .

It is a cyclic number.

It is not a de Polignac number, because 402021541 - 2⁹ = 402021029 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (402027541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 201010770 + 201010771.

It is an arithmetic number, because the mean of its divisors is an integer number (201010771).

Almost surely, 2^402021541 is an apocalyptic number.

It is an amenable number.

402021541 is a deficient number, since it is larger than the sum of its proper divisors (1).

402021541 is an equidigital number, since it uses as much as digits as its factorization.

402021541 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 320, while the sum is 19.

The square root of 402021541 is about 20050.4748322827. The cubic root of 402021541 is about 738.0454513567.

Adding to 402021541 its reverse (145120204), we get a palindrome (547141745).

The spelling of 402021541 in words is "four hundred two million, twenty-one thousand, five hundred forty-one".