1637641 has 2 divisors, whose sum is σ = 1637642. Its totient is φ = 1637640.

The previous prime is 1637639. The next prime is 1637677. The reversal of 1637641 is 1467361.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1550025 + 87616 = 1245^2 + 296^2 .

It is a cyclic number.

It is not a de Polignac number, because 1637641 - 2¹ = 1637639 is a prime.

Together with 1637639, it forms a pair of twin primes.

It is equal to p₁₂₃₇₉₆ and since 1637641 and 123796 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (1637611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 818820 + 818821.

It is an arithmetic number, because the mean of its divisors is an integer number (818821).

2^1637641 is an apocalyptic number.

It is an amenable number.

1637641 is a deficient number, since it is larger than the sum of its proper divisors (1).

1637641 is an equidigital number, since it uses as much as digits as its factorization.

1637641 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 1637641 is about 1279.7034812799. The cubic root of 1637641 is about 117.8708008484.

It can be divided in two parts, 1637 and 641, that added together give a triangular number (2278 = T₆₇).

The spelling of 1637641 in words is "one million, six hundred thirty-seven thousand, six hundred forty-one".