1663611253 has 4 divisors (see below), whose sum is σ = 1751169760. Its totient is φ = 1576052748.

The previous prime is 1663611251. The next prime is 1663611263. The reversal of 1663611253 is 3521163661.

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, and also an emirpimes, since its reverse is a distinct semiprime: 3521163661 = 43 ⋅81887527.

It is a cyclic number.

It is not a de Polignac number, because 1663611253 - 2¹ = 1663611251 is a prime.

It is a super-2 number, since 2×1663611253² = 5535204802216460018, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1663611251) 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, 43779225 + ... + 43779262.

It is an arithmetic number, because the mean of its divisors is an integer number (437792440).

Almost surely, 2^1663611253 is an apocalyptic number.

It is an amenable number.

1663611253 is a deficient number, since it is larger than the sum of its proper divisors (87558507).

1663611253 is an equidigital number, since it uses as much as digits as its factorization.

1663611253 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87558506.

The product of its digits is 19440, while the sum is 34.

The square root of 1663611253 is about 40787.3908579600. The cubic root of 1663611253 is about 1184.9061396101.

It can be divided in two parts, 16636 and 11253, that added together give a square (27889 = 167²).

The spelling of 1663611253 in words is "one billion, six hundred sixty-three million, six hundred eleven thousand, two hundred fifty-three".