645574019 has 2 divisors, whose sum is σ = 645574020. Its totient is φ = 645574018.

The previous prime is 645574009. The next prime is 645574037. The reversal of 645574019 is 910475546.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 645574019 - 2¹² = 645569923 is a prime.

It is a super-2 number, since 2×645574019² = 833531628015624722, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (645574009) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 322787009 + 322787010.

It is an arithmetic number, because the mean of its divisors is an integer number (322787010).

Almost surely, 2^645574019 is an apocalyptic number.

645574019 is a deficient number, since it is larger than the sum of its proper divisors (1).

645574019 is an equidigital number, since it uses as much as digits as its factorization.

645574019 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 151200, while the sum is 41.

The square root of 645574019 is about 25408.1486732111. The cubic root of 645574019 is about 864.2684935693.

The spelling of 645574019 in words is "six hundred forty-five million, five hundred seventy-four thousand, nineteen".