642743737 has 4 divisors (see below), whose sum is σ = 642920740. Its totient is φ = 642566736.

The previous prime is 642743729. The next prime is 642743743. The reversal of 642743737 is 737347246.

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

It can be written as a sum of positive squares in 2 ways, for example, as 112869376 + 529874361 = 10624^2 + 23019^2 .

It is a cyclic number.

It is not a de Polignac number, because 642743737 - 2³ = 642743729 is a prime.

It is a super-2 number, since 2×642743737² = 826239022905450338, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 642743693 and 642743702.

It is not an unprimeable number, because it can be changed into a prime (642743707) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 82938 + ... + 90355.

It is an arithmetic number, because the mean of its divisors is an integer number (160730185).

Almost surely, 2^642743737 is an apocalyptic number.

It is an amenable number.

642743737 is a deficient number, since it is larger than the sum of its proper divisors (177003).

642743737 is a wasteful number, since it uses less digits than its factorization.

642743737 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 177002.

The product of its digits is 592704, while the sum is 43.

The square root of 642743737 is about 25352.3911495543. The cubic root of 642743737 is about 863.0036207943.

The spelling of 642743737 in words is "six hundred forty-two million, seven hundred forty-three thousand, seven hundred thirty-seven".