642853829 has 2 divisors, whose sum is σ = 642853830. Its totient is φ = 642853828.

The previous prime is 642853787. The next prime is 642853843. The reversal of 642853829 is 928358246.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 586753729 + 56100100 = 24223^2 + 7490^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-642853829 is a prime.

It is a super-2 number, since 2×642853829² = 826522090919922482, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (642853859) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 321426914 + 321426915.

It is an arithmetic number, because the mean of its divisors is an integer number (321426915).

Almost surely, 2^642853829 is an apocalyptic number.

It is an amenable number.

642853829 is a deficient number, since it is larger than the sum of its proper divisors (1).

642853829 is an equidigital number, since it uses as much as digits as its factorization.

642853829 is an evil number, because the sum of its binary digits is even.

The product of its digits is 829440, while the sum is 47.

The square root of 642853829 is about 25354.5622916271. The cubic root of 642853829 is about 863.0528910115.

The spelling of 642853829 in words is "six hundred forty-two million, eight hundred fifty-three thousand, eight hundred twenty-nine".