642066751 has 8 divisors (see below), whose sum is σ = 654881760. Its totient is φ = 629277792.

The previous prime is 642066749. The next prime is 642066779. The reversal of 642066751 is 157660246.

It is a happy number.

642066751 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 642066751 - 2¹ = 642066749 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 642066751.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642066701) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 47710 + ... + 59668.

It is an arithmetic number, because the mean of its divisors is an integer number (81860220).

Almost surely, 2^642066751 is an apocalyptic number.

642066751 is a deficient number, since it is larger than the sum of its proper divisors (12815009).

642066751 is a wasteful number, since it uses less digits than its factorization.

642066751 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13025.

The product of its (nonzero) digits is 60480, while the sum is 37.

The square root of 642066751 is about 25339.0361103180. The cubic root of 642066751 is about 862.7005209335.

The spelling of 642066751 in words is "six hundred forty-two million, sixty-six thousand, seven hundred fifty-one".