1531721253 has 32 divisors (see below), whose sum is σ = 2160525312. Its totient is φ = 963892800.

The previous prime is 1531721251. The next prime is 1531721287. The reversal of 1531721253 is 3521271351.

It is not a de Polignac number, because 1531721253 - 2¹ = 1531721251 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1531721253.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1531721251) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 940626 + ... + 942252.

It is an arithmetic number, because the mean of its divisors is an integer number (67516416).

Almost surely, 2^1531721253 is an apocalyptic number.

It is an amenable number.

1531721253 is a deficient number, since it is larger than the sum of its proper divisors (628804059).

1531721253 is a wasteful number, since it uses less digits than its factorization.

1531721253 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1905.

The product of its digits is 6300, while the sum is 30.

The square root of 1531721253 is about 39137.2105929894. The cubic root of 1531721253 is about 1152.7273020805.

The spelling of 1531721253 in words is "one billion, five hundred thirty-one million, seven hundred twenty-one thousand, two hundred fifty-three".