402112021 has 2 divisors, whose sum is σ = 402112022. Its totient is φ = 402112020.

The previous prime is 402112001. The next prime is 402112027. The reversal of 402112021 is 120211204.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 339480625 + 62631396 = 18425^2 + 7914^2 .

It is a cyclic number.

It is not a de Polignac number, because 402112021 - 2⁵ = 402111989 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 402111992 and 402112010.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (402112027) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 201056010 + 201056011.

It is an arithmetic number, because the mean of its divisors is an integer number (201056011).

Almost surely, 2^402112021 is an apocalyptic number.

It is an amenable number.

402112021 is a deficient number, since it is larger than the sum of its proper divisors (1).

402112021 is an equidigital number, since it uses as much as digits as its factorization.

402112021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 402112021 is about 20052.7310110119. The cubic root of 402112021 is about 738.1008160047.

Adding to 402112021 its reverse (120211204), we get a palindrome (522323225).

The spelling of 402112021 in words is "four hundred two million, one hundred twelve thousand, twenty-one".