721422581 has 4 divisors (see below), whose sum is σ = 787006464. Its totient is φ = 655838700.

The previous prime is 721422553. The next prime is 721422601. The reversal of 721422581 is 185224127.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 721422581 - 2¹⁴ = 721406197 is a prime.

It is a super-2 number, since 2×721422581² = 1040901080753403122, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721422521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 32791925 + ... + 32791946.

It is an arithmetic number, because the mean of its divisors is an integer number (196751616).

Almost surely, 2^721422581 is an apocalyptic number.

It is an amenable number.

721422581 is a deficient number, since it is larger than the sum of its proper divisors (65583883).

721422581 is a wasteful number, since it uses less digits than its factorization.

721422581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65583882.

The product of its digits is 8960, while the sum is 32.

The square root of 721422581 is about 26859.3108809590. The cubic root of 721422581 is about 896.8708536774.

The spelling of 721422581 in words is "seven hundred twenty-one million, four hundred twenty-two thousand, five hundred eighty-one".