705540647921 has 4 divisors (see below), whose sum is σ = 706776271344. Its totient is φ = 704305024500.

The previous prime is 705540647897. The next prime is 705540647927. The reversal of 705540647921 is 129746045507.

It is a happy number.

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 705540647921 - 2¹⁰ = 705540646897 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 705540647921.

It is not an unprimeable number, because it can be changed into a prime (705540647927) 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, 617810855 + ... + 617811996.

It is an arithmetic number, because the mean of its divisors is an integer number (176694067836).

Almost surely, 2^705540647921 is an apocalyptic number.

It is an amenable number.

705540647921 is a deficient number, since it is larger than the sum of its proper divisors (1235623423).

705540647921 is a wasteful number, since it uses less digits than its factorization.

705540647921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1235623422.

The product of its (nonzero) digits is 2116800, while the sum is 50.

The spelling of 705540647921 in words is "seven hundred five billion, five hundred forty million, six hundred forty-seven thousand, nine hundred twenty-one".