1631643 has 32 divisors (see below), whose sum is σ = 2612736. Its totient is φ = 895488.

The previous prime is 1631639. The next prime is 1631647. The reversal of 1631643 is 3461361.

It is an interprime number because it is at equal distance from previous prime (1631639) and next prime (1631647).

It is not a de Polignac number, because 1631643 - 2² = 1631639 is a prime.

It is not an unprimeable number, because it can be changed into a prime (1631647) 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, 15196 + ... + 15302.

It is an arithmetic number, because the mean of its divisors is an integer number (81648).

2^1631643 is an apocalyptic number.

1631643 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

1631643 is a deficient number, since it is larger than the sum of its proper divisors (981093).

1631643 is a wasteful number, since it uses less digits than its factorization.

1631643 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 163.

The product of its digits is 1296, while the sum is 24.

The square root of 1631643 is about 1277.3578198766. The cubic root of 1631643 is about 117.7267208455.

The spelling of 1631643 in words is "one million, six hundred thirty-one thousand, six hundred forty-three".