721221431 has 8 divisors (see below), whose sum is σ = 824472864. Its totient is φ = 618024960.

The previous prime is 721221401. The next prime is 721221463. The reversal of 721221431 is 134122127.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 721221431 - 2⁶ = 721221367 is a prime.

It is a super-2 number, since 2×721221431² = 1040320705067375522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 721221397 and 721221406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (721221401) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19871 + ... + 42863.

It is an arithmetic number, because the mean of its divisors is an integer number (103059108).

Almost surely, 2^721221431 is an apocalyptic number.

721221431 is a deficient number, since it is larger than the sum of its proper divisors (103251433).

721221431 is a wasteful number, since it uses less digits than its factorization.

721221431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27481.

The product of its digits is 672, while the sum is 23.

The square root of 721221431 is about 26855.5661083508. The cubic root of 721221431 is about 896.7874895269.

Adding to 721221431 its reverse (134122127), we get a palindrome (855343558).

The spelling of 721221431 in words is "seven hundred twenty-one million, two hundred twenty-one thousand, four hundred thirty-one".