1641916997 has 4 divisors (see below), whose sum is σ = 1876476576. Its totient is φ = 1407357420.

The previous prime is 1641916981. The next prime is 1641916999. The reversal of 1641916997 is 7996191461.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 1641916997 - 2⁴ = 1641916981 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 (1641916999) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 117279779 + ... + 117279792.

It is an arithmetic number, because the mean of its divisors is an integer number (469119144).

Almost surely, 2^1641916997 is an apocalyptic number.

It is an amenable number.

1641916997 is a deficient number, since it is larger than the sum of its proper divisors (234559579).

1641916997 is an equidigital number, since it uses as much as digits as its factorization.

1641916997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 234559578.

The product of its digits is 734832, while the sum is 53.

The square root of 1641916997 is about 40520.5749835809. The cubic root of 1641916997 is about 1179.7330136651.

The spelling of 1641916997 in words is "one billion, six hundred forty-one million, nine hundred sixteen thousand, nine hundred ninety-seven".