642605129 has 4 divisors (see below), whose sum is σ = 642748176. Its totient is φ = 642462084.

The previous prime is 642605111. The next prime is 642605147. The reversal of 642605129 is 921506246.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is an interprime number because it is at equal distance from previous prime (642605111) and next prime (642605147).

It is a cyclic number.

It is not a de Polignac number, because 642605129 - 2⁸ = 642604873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (642605179) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64559 + ... + 73844.

It is an arithmetic number, because the mean of its divisors is an integer number (160687044).

Almost surely, 2^642605129 is an apocalyptic number.

It is an amenable number.

642605129 is a deficient number, since it is larger than the sum of its proper divisors (143047).

642605129 is a wasteful number, since it uses less digits than its factorization.

642605129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143046.

The product of its (nonzero) digits is 25920, while the sum is 35.

The square root of 642605129 is about 25349.6573744104. The cubic root of 642605129 is about 862.9415806173.

The spelling of 642605129 in words is "six hundred forty-two million, six hundred five thousand, one hundred twenty-nine".