642606266 has 4 divisors (see below), whose sum is σ = 963909402. Its totient is φ = 321303132.

The previous prime is 642606259. The next prime is 642606271. The reversal of 642606266 is 662606246.

642606266 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 615784225 + 26822041 = 24815^2 + 5179^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 160651565 + ... + 160651568.

Almost surely, 2^642606266 is an apocalyptic number.

642606266 is a deficient number, since it is larger than the sum of its proper divisors (321303136).

642606266 is a wasteful number, since it uses less digits than its factorization.

642606266 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 321303135.

The product of its (nonzero) digits is 124416, while the sum is 38.

The square root of 642606266 is about 25349.6798007391. The cubic root of 642606266 is about 862.9420895686.

The spelling of 642606266 in words is "six hundred forty-two million, six hundred six thousand, two hundred sixty-six".