1491887101 has 4 divisors (see below), whose sum is σ = 1532208412. Its totient is φ = 1451565792.

The previous prime is 1491887099. The next prime is 1491887129. The reversal of 1491887101 is 1017881941.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1017881941 = 2251 ⋅452191.

It can be written as a sum of positive squares in 2 ways, for example, as 1435652100 + 56235001 = 37890^2 + 7499^2 .

It is a cyclic number.

It is not a de Polignac number, because 1491887101 - 2¹ = 1491887099 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1491887141) 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 3 ways as a sum of consecutive naturals, for example, 20160600 + ... + 20160673.

It is an arithmetic number, because the mean of its divisors is an integer number (383052103).

Almost surely, 2^1491887101 is an apocalyptic number.

It is an amenable number.

1491887101 is a deficient number, since it is larger than the sum of its proper divisors (40321311).

1491887101 is an equidigital number, since it uses as much as digits as its factorization.

1491887101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40321310.

The product of its (nonzero) digits is 16128, while the sum is 40.

The square root of 1491887101 is about 38624.9543818501. The cubic root of 1491887101 is about 1142.6467437405.

The spelling of 1491887101 in words is "one billion, four hundred ninety-one million, eight hundred eighty-seven thousand, one hundred one".