1641631021 has 8 divisors (see below), whose sum is σ = 1701935424. Its totient is φ = 1582291680.

The previous prime is 1641631001. The next prime is 1641631031. The reversal of 1641631021 is 1201361461.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1641631021 - 2⁹ = 1641630509 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 (1641631001) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 237801 + ... + 244606.

It is an arithmetic number, because the mean of its divisors is an integer number (212741928).

Almost surely, 2^1641631021 is an apocalyptic number.

It is an amenable number.

1641631021 is a deficient number, since it is larger than the sum of its proper divisors (60304403).

1641631021 is an equidigital number, since it uses as much as digits as its factorization.

1641631021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 482531.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 1641631021 is about 40517.0460547163. The cubic root of 1641631021 is about 1179.6645175276.

Adding to 1641631021 its reverse (1201361461), we get a palindrome (2842992482).

The spelling of 1641631021 in words is "one billion, six hundred forty-one million, six hundred thirty-one thousand, twenty-one".