894223069721 has 4 divisors (see below), whose sum is σ = 894386343972. Its totient is φ = 894059795472.

The previous prime is 894223069711. The next prime is 894223069759. The reversal of 894223069721 is 127960322498.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 891581623696 + 2641446025 = 944236^2 + 51395^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-894223069721 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (894223069711) 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, 81628910 + ... + 81639863.

It is an arithmetic number, because the mean of its divisors is an integer number (223596585993).

Almost surely, 2^894223069721 is an apocalyptic number.

It is an amenable number.

894223069721 is a deficient number, since it is larger than the sum of its proper divisors (163274251).

894223069721 is a wasteful number, since it uses less digits than its factorization.

894223069721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 163274250.

The product of its (nonzero) digits is 2612736, while the sum is 53.

The spelling of 894223069721 in words is "eight hundred ninety-four billion, two hundred twenty-three million, sixty-nine thousand, seven hundred twenty-one".