721223534 has 4 divisors (see below), whose sum is σ = 1081835304. Its totient is φ = 360611766.

The previous prime is 721223491. The next prime is 721223537. The reversal of 721223534 is 435322127.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 435322127 = 23 ⋅18927049.

It is a junction number, because it is equal to n+sod(n) for n = 721223497 and 721223506.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721223537) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 180305882 + ... + 180305885.

It is an arithmetic number, because the mean of its divisors is an integer number (270458826).

Almost surely, 2^721223534 is an apocalyptic number.

721223534 is a deficient number, since it is larger than the sum of its proper divisors (360611770).

721223534 is a wasteful number, since it uses less digits than its factorization.

721223534 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 360611769.

The product of its digits is 10080, while the sum is 29.

The square root of 721223534 is about 26855.6052622167. The cubic root of 721223534 is about 896.7883611696.

The spelling of 721223534 in words is "seven hundred twenty-one million, two hundred twenty-three thousand, five hundred thirty-four".