641440739 has 4 divisors (see below), whose sum is σ = 641492424. Its totient is φ = 641389056.

The previous prime is 641440733. The next prime is 641440759. The reversal of 641440739 is 937044146.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-641440739 is a prime.

It is a super-2 number, since 2×641440739² = 822892443297732242, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (641440733) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5219 + ... + 36195.

It is an arithmetic number, because the mean of its divisors is an integer number (160373106).

Almost surely, 2^641440739 is an apocalyptic number.

641440739 is a deficient number, since it is larger than the sum of its proper divisors (51685).

641440739 is a wasteful number, since it uses less digits than its factorization.

641440739 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51684.

The product of its (nonzero) digits is 72576, while the sum is 38.

The square root of 641440739 is about 25326.6803786047. The cubic root of 641440739 is about 862.4200534734.

The spelling of 641440739 in words is "six hundred forty-one million, four hundred forty thousand, seven hundred thirty-nine".