402541540021 has 2 divisors, whose sum is σ = 402541540022. Its totient is φ = 402541540020.

The previous prime is 402541540007. The next prime is 402541540087. The reversal of 402541540021 is 120045145204.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 399898140625 + 2643399396 = 632375^2 + 51414^2 .

It is a cyclic number.

It is not a de Polignac number, because 402541540021 - 2¹¹ = 402541537973 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (402541520021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 201270770010 + 201270770011.

It is an arithmetic number, because the mean of its divisors is an integer number (201270770011).

Almost surely, 2^402541540021 is an apocalyptic number.

It is an amenable number.

402541540021 is a deficient number, since it is larger than the sum of its proper divisors (1).

402541540021 is an equidigital number, since it uses as much as digits as its factorization.

402541540021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 6400, while the sum is 28.

Adding to 402541540021 its reverse (120045145204), we get a palindrome (522586685225).

The spelling of 402541540021 in words is "four hundred two billion, five hundred forty-one million, five hundred forty thousand, twenty-one".