406242521 has 2 divisors, whose sum is σ = 406242522. Its totient is φ = 406242520.

The previous prime is 406242497. The next prime is 406242541. The reversal of 406242521 is 125242604.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 406224025 + 18496 = 20155^2 + 136^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-406242521 is a prime.

It is a Chen prime.

It is equal to p_21651371 and since 406242521 and 21651371 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (406242541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 203121260 + 203121261.

It is an arithmetic number, because the mean of its divisors is an integer number (203121261).

Almost surely, 2^406242521 is an apocalyptic number.

It is an amenable number.

406242521 is a deficient number, since it is larger than the sum of its proper divisors (1).

406242521 is an equidigital number, since it uses as much as digits as its factorization.

406242521 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3840, while the sum is 26.

The square root of 406242521 is about 20155.4588387365. The cubic root of 406242521 is about 740.6194721492.

The spelling of 406242521 in words is "four hundred six million, two hundred forty-two thousand, five hundred twenty-one".