42640737 has 4 divisors (see below), whose sum is σ = 56854320. Its totient is φ = 28427156.

The previous prime is 42640733. The next prime is 42640747. The reversal of 42640737 is 73704624.

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 a cyclic number.

It is not a de Polignac number, because 42640737 - 2² = 42640733 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 42640698 and 42640707.

It is not an unprimeable number, because it can be changed into a prime (42640733) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7106787 + ... + 7106792.

It is an arithmetic number, because the mean of its divisors is an integer number (14213580).

Almost surely, 2^42640737 is an apocalyptic number.

It is an amenable number.

42640737 is a deficient number, since it is larger than the sum of its proper divisors (14213583).

42640737 is a wasteful number, since it uses less digits than its factorization.

42640737 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14213582.

The product of its (nonzero) digits is 28224, while the sum is 33.

The square root of 42640737 is about 6529.9875191305. The cubic root of 42640737 is about 349.3613851430.

The spelling of 42640737 in words is "forty-two million, six hundred forty thousand, seven hundred thirty-seven".