705868021 has 4 divisors (see below), whose sum is σ = 708095052. Its totient is φ = 703640992.

The previous prime is 705868003. The next prime is 705868049. The reversal of 705868021 is 120868507.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 120868507 = 1237 ⋅97711.

It can be written as a sum of positive squares in 2 ways, for example, as 88096996 + 617771025 = 9386^2 + 24855^2 .

It is a cyclic number.

It is not a de Polignac number, because 705868021 - 2⁷ = 705867893 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 (705868061) 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, 1113040 + ... + 1113673.

It is an arithmetic number, because the mean of its divisors is an integer number (177023763).

Almost surely, 2^705868021 is an apocalyptic number.

It is an amenable number.

705868021 is a deficient number, since it is larger than the sum of its proper divisors (2227031).

705868021 is a wasteful number, since it uses less digits than its factorization.

705868021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2227030.

The product of its (nonzero) digits is 26880, while the sum is 37.

The square root of 705868021 is about 26568.1768474993. The cubic root of 705868021 is about 890.3781673643.

The spelling of 705868021 in words is "seven hundred five million, eight hundred sixty-eight thousand, twenty-one".