1491898663 has 4 divisors (see below), whose sum is σ = 1496326000. Its totient is φ = 1487471328.

The previous prime is 1491898637. The next prime is 1491898711. The reversal of 1491898663 is 3668981941.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3668981941 = 4507 ⋅814063.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1491898663 is a prime.

It is a super-2 number, since 2×1491898663² = 4451523241322375138, 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 (1491898613) 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, 2213163 + ... + 2213836.

It is an arithmetic number, because the mean of its divisors is an integer number (374081500).

Almost surely, 2^1491898663 is an apocalyptic number.

1491898663 is a deficient number, since it is larger than the sum of its proper divisors (4427337).

1491898663 is an equidigital number, since it uses as much as digits as its factorization.

1491898663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4427336.

The product of its digits is 2239488, while the sum is 55.

The square root of 1491898663 is about 38625.1040516398. The cubic root of 1491898663 is about 1142.6496955384.

The spelling of 1491898663 in words is "one billion, four hundred ninety-one million, eight hundred ninety-eight thousand, six hundred sixty-three".