642791693 has 8 divisors (see below), whose sum is σ = 662608512. Its totient is φ = 623230816.

The previous prime is 642791689. The next prime is 642791701. The reversal of 642791693 is 396197246.

It is a happy number.

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 642791693 - 2² = 642791689 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (47).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (642791683) 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, 58880 + ... + 68937.

It is an arithmetic number, because the mean of its divisors is an integer number (82826064).

Almost surely, 2^642791693 is an apocalyptic number.

It is an amenable number.

642791693 is a deficient number, since it is larger than the sum of its proper divisors (19816819).

642791693 is a wasteful number, since it uses less digits than its factorization.

642791693 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 127971.

The product of its digits is 489888, while the sum is 47.

The square root of 642791693 is about 25353.3369204135. The cubic root of 642791693 is about 863.0250835588.

The spelling of 642791693 in words is "six hundred forty-two million, seven hundred ninety-one thousand, six hundred ninety-three".