42661640257 has 4 divisors (see below), whose sum is σ = 42734318256. Its totient is φ = 42588962260.

The previous prime is 42661640249. The next prime is 42661640279. The reversal of 42661640257 is 75204616624.

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 42661640257 - 2³ = 42661640249 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42661640227) 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, 36338119 + ... + 36339292.

It is an arithmetic number, because the mean of its divisors is an integer number (10683579564).

Almost surely, 2^42661640257 is an apocalyptic number.

It is an amenable number.

42661640257 is a deficient number, since it is larger than the sum of its proper divisors (72677999).

42661640257 is an equidigital number, since it uses as much as digits as its factorization.

42661640257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72677998.

The product of its (nonzero) digits is 483840, while the sum is 43.

The spelling of 42661640257 in words is "forty-two billion, six hundred sixty-one million, six hundred forty thousand, two hundred fifty-seven".