1431432721 has 4 divisors (see below), whose sum is σ = 1480792500. Its totient is φ = 1382072944.

The previous prime is 1431432683. The next prime is 1431432767. The reversal of 1431432721 is 1272341341.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 837292096 + 594140625 = 28936^2 + 24375^2 .

It is a cyclic number.

It is not a de Polignac number, because 1431432721 - 2¹⁹ = 1430908433 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1431432721.

It is not an unprimeable number, because it can be changed into a prime (1431432791) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24679846 + ... + 24679903.

It is an arithmetic number, because the mean of its divisors is an integer number (370198125).

Almost surely, 2^1431432721 is an apocalyptic number.

It is an amenable number.

1431432721 is a deficient number, since it is larger than the sum of its proper divisors (49359779).

1431432721 is an equidigital number, since it uses as much as digits as its factorization.

1431432721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49359778.

The product of its digits is 4032, while the sum is 28.

The square root of 1431432721 is about 37834.2797076937. The cubic root of 1431432721 is about 1126.9993013829. Note that the first 3 decimals are identical.

The spelling of 1431432721 in words is "one billion, four hundred thirty-one million, four hundred thirty-two thousand, seven hundred twenty-one".