723543921 has 48 divisors (see below), whose sum is σ = 1158393600. Its totient is φ = 449962128.

The previous prime is 723543907. The next prime is 723543943. The reversal of 723543921 is 129345327.

723543921 is a `hidden beast` number, since 7 + 23 + 543 + 92 + 1 = 666.

It is not a de Polignac number, because 723543921 - 2¹¹ = 723541873 is a prime.

It is not an unprimeable number, because it can be changed into a prime (723543421) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 308170 + ... + 310508.

It is an arithmetic number, because the mean of its divisors is an integer number (24133200).

Almost surely, 2^723543921 is an apocalyptic number.

It is an amenable number.

723543921 is a deficient number, since it is larger than the sum of its proper divisors (434849679).

723543921 is a wasteful number, since it uses less digits than its factorization.

723543921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2440 (or 2428 counting only the distinct ones).

The product of its digits is 45360, while the sum is 36.

The square root of 723543921 is about 26898.7717377578. The cubic root of 723543921 is about 897.7490750677.

It can be divided in two parts, 723 and 543921, that added together give a square (544644 = 738²).

The spelling of 723543921 in words is "seven hundred twenty-three million, five hundred forty-three thousand, nine hundred twenty-one".