1491729621 has 8 divisors (see below), whose sum is σ = 1989238944. Its totient is φ = 994353360.

The previous prime is 1491729581. The next prime is 1491729647. The reversal of 1491729621 is 1269271941.

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

It is not a de Polignac number, because 1491729621 - 2¹⁵ = 1491696853 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1491729221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3231 + ... + 54716.

It is an arithmetic number, because the mean of its divisors is an integer number (248654868).

Almost surely, 2^1491729621 is an apocalyptic number.

It is an amenable number.

1491729621 is a deficient number, since it is larger than the sum of its proper divisors (497509323).

1491729621 is an equidigital number, since it uses as much as digits as its factorization.

1491729621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 66531.

The product of its digits is 54432, while the sum is 42.

The square root of 1491729621 is about 38622.9157495909. The cubic root of 1491729621 is about 1142.6065373154.

The spelling of 1491729621 in words is "one billion, four hundred ninety-one million, seven hundred twenty-nine thousand, six hundred twenty-one".