1491643 has 2 divisors, whose sum is σ = 1491644. Its totient is φ = 1491642.

The previous prime is 1491641. The next prime is 1491649. The reversal of 1491643 is 3461941.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1491643 - 2¹ = 1491641 is a prime.

Together with 1491641, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (1491641) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 745821 + 745822.

It is an arithmetic number, because the mean of its divisors is an integer number (745822).

2^1491643 is an apocalyptic number.

1491643 is a deficient number, since it is larger than the sum of its proper divisors (1).

1491643 is an equidigital number, since it uses as much as digits as its factorization.

1491643 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2592, while the sum is 28.

The square root of 1491643 is about 1221.3283751719. The cubic root of 1491643 is about 114.2584420788.

The spelling of 1491643 in words is "one million, four hundred ninety-one thousand, six hundred forty-three".