812250721644 has 12 divisors (see below), whose sum is σ = 1895251683864. Its totient is φ = 270750240544.

The previous prime is 812250721643. The next prime is 812250721669. The reversal of 812250721644 is 446127052218.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×812250721644² (a number of 25 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 812250721596 and 812250721605.

It is not an unprimeable number, because it can be changed into a prime (812250721643) 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, 33843780057 + ... + 33843780080.

It is an arithmetic number, because the mean of its divisors is an integer number (157937640322).

Almost surely, 2^812250721644 is an apocalyptic number.

It is an amenable number.

812250721644 is an abundant number, since it is smaller than the sum of its proper divisors (1083000962220).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

812250721644 is a wasteful number, since it uses less digits than its factorization.

812250721644 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67687560144 (or 67687560142 counting only the distinct ones).

The product of its (nonzero) digits is 215040, while the sum is 42.

The spelling of 812250721644 in words is "eight hundred twelve billion, two hundred fifty million, seven hundred twenty-one thousand, six hundred forty-four".