743943661 has 4 divisors (see below), whose sum is σ = 744457824. Its totient is φ = 743429500.

The previous prime is 743943659. The next prime is 743943709. The reversal of 743943661 is 166349347.

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, and also an emirpimes, since its reverse is a distinct semiprime: 166349347 = 83 ⋅2004209.

It is a cyclic number.

It is not a de Polignac number, because 743943661 - 2¹ = 743943659 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (743943601) 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, 254905 + ... + 257806.

It is an arithmetic number, because the mean of its divisors is an integer number (186114456).

Almost surely, 2^743943661 is an apocalyptic number.

It is an amenable number.

743943661 is a deficient number, since it is larger than the sum of its proper divisors (514163).

743943661 is a wasteful number, since it uses less digits than its factorization.

743943661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 514162.

The product of its digits is 326592, while the sum is 43.

The square root of 743943661 is about 27275.3306304433. The cubic root of 743943661 is about 906.1081065456.

The spelling of 743943661 in words is "seven hundred forty-three million, nine hundred forty-three thousand, six hundred sixty-one".