845423721 has 12 divisors (see below), whose sum is σ = 1223681472. Its totient is φ = 562455576.

The previous prime is 845423701. The next prime is 845423741. The reversal of 845423721 is 127324548.

It is a happy number.

845423721 is a `hidden beast` number, since 84 + 542 + 37 + 2 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (845423701) and next prime (845423741).

It is not a de Polignac number, because 845423721 - 2²⁶ = 778314857 is a prime.

It is not an unprimeable number, because it can be changed into a prime (845423701) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 92061 + ... + 100826.

It is an arithmetic number, because the mean of its divisors is an integer number (101973456).

Almost surely, 2^845423721 is an apocalyptic number.

It is an amenable number.

845423721 is a deficient number, since it is larger than the sum of its proper divisors (378257751).

845423721 is a wasteful number, since it uses less digits than its factorization.

845423721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 193380 (or 193377 counting only the distinct ones).

The product of its digits is 53760, while the sum is 36.

The square root of 845423721 is about 29076.1710168309. The cubic root of 845423721 is about 945.5651914199.

The spelling of 845423721 in words is "eight hundred forty-five million, four hundred twenty-three thousand, seven hundred twenty-one".