642170357 has 2 divisors, whose sum is σ = 642170358. Its totient is φ = 642170356.

The previous prime is 642170329. The next prime is 642170377. The reversal of 642170357 is 753071246.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 641811556 + 358801 = 25334^2 + 599^2 .

It is a cyclic number.

It is not a de Polignac number, because 642170357 - 2¹⁶ = 642104821 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (642170377) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321085178 + 321085179.

It is an arithmetic number, because the mean of its divisors is an integer number (321085179).

Almost surely, 2^642170357 is an apocalyptic number.

It is an amenable number.

642170357 is a deficient number, since it is larger than the sum of its proper divisors (1).

642170357 is an equidigital number, since it uses as much as digits as its factorization.

642170357 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 35280, while the sum is 35.

The square root of 642170357 is about 25341.0804229023. The cubic root of 642170357 is about 862.7469211678.

The spelling of 642170357 in words is "six hundred forty-two million, one hundred seventy thousand, three hundred fifty-seven".