420740557 has 2 divisors, whose sum is σ = 420740558. Its totient is φ = 420740556.

The previous prime is 420740549. The next prime is 420740561. The reversal of 420740557 is 755047024.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 398641156 + 22099401 = 19966^2 + 4701^2 .

It is a cyclic number.

It is not a de Polignac number, because 420740557 - 2³ = 420740549 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (420740057) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 210370278 + 210370279.

It is an arithmetic number, because the mean of its divisors is an integer number (210370279).

Almost surely, 2^420740557 is an apocalyptic number.

It is an amenable number.

420740557 is a deficient number, since it is larger than the sum of its proper divisors (1).

420740557 is an equidigital number, since it uses as much as digits as its factorization.

420740557 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 39200, while the sum is 34.

The square root of 420740557 is about 20511.9613152911. The cubic root of 420740557 is about 749.3271339971.

The spelling of 420740557 in words is "four hundred twenty million, seven hundred forty thousand, five hundred fifty-seven".