1641781069 has 4 divisors (see below), whose sum is σ = 1738356444. Its totient is φ = 1545205696.

The previous prime is 1641781003. The next prime is 1641781073. The reversal of 1641781069 is 9601871461.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1296936169 + 344844900 = 36013^2 + 18570^2 .

It is a cyclic number.

It is not a de Polignac number, because 1641781069 - 2¹¹ = 1641779021 is a prime.

It is a super-2 number, since 2×1641781069² = 5390890157053565522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1641781369) 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, 48287662 + ... + 48287695.

It is an arithmetic number, because the mean of its divisors is an integer number (434589111).

Almost surely, 2^1641781069 is an apocalyptic number.

It is an amenable number.

1641781069 is a deficient number, since it is larger than the sum of its proper divisors (96575375).

1641781069 is an equidigital number, since it uses as much as digits as its factorization.

1641781069 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 96575374.

The product of its (nonzero) digits is 72576, while the sum is 43.

The square root of 1641781069 is about 40518.8976775035. The cubic root of 1641781069 is about 1179.7004575788.

The spelling of 1641781069 in words is "one billion, six hundred forty-one million, seven hundred eighty-one thousand, sixty-nine".