1641637 has 2 divisors, whose sum is σ = 1641638. Its totient is φ = 1641636.

The previous prime is 1641631. The next prime is 1641641. The reversal of 1641637 is 7361461.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1640961 + 676 = 1281^2 + 26^2 .

It is an emirp because it is prime and its reverse (7361461) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1641637 - 2⁷ = 1641509 is a prime.

1641637 is a lucky number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1641631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 820818 + 820819.

It is an arithmetic number, because the mean of its divisors is an integer number (820819).

2^1641637 is an apocalyptic number.

It is an amenable number.

1641637 is a deficient number, since it is larger than the sum of its proper divisors (1).

1641637 is an equidigital number, since it uses as much as digits as its factorization.

1641637 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3024, while the sum is 28.

The square root of 1641637 is about 1281.2638291937. The cubic root of 1641637 is about 117.9665949682.

It can be divided in two parts, 1641 and 637, that added together give a triangular number (2278 = T₆₇).

The spelling of 1641637 in words is "one million, six hundred forty-one thousand, six hundred thirty-seven".