642656227 has 2 divisors, whose sum is σ = 642656228. Its totient is φ = 642656226.

The previous prime is 642656197. The next prime is 642656249. The reversal of 642656227 is 722656246.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-642656227 is a prime.

It is a super-2 number, since 2×642656227² = 826014052203751058, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 642656227.

It is not a weakly prime, because it can be changed into another prime (642656297) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321328113 + 321328114.

It is an arithmetic number, because the mean of its divisors is an integer number (321328114).

Almost surely, 2^642656227 is an apocalyptic number.

642656227 is a deficient number, since it is larger than the sum of its proper divisors (1).

642656227 is an equidigital number, since it uses as much as digits as its factorization.

642656227 is an evil number, because the sum of its binary digits is even.

The product of its digits is 241920, while the sum is 40.

The square root of 642656227 is about 25350.6652180963. The cubic root of 642656227 is about 862.9644528387.

The spelling of 642656227 in words is "six hundred forty-two million, six hundred fifty-six thousand, two hundred twenty-seven".