1641823949 has 2 divisors, whose sum is σ = 1641823950. Its totient is φ = 1641823948.

The previous prime is 1641823933. The next prime is 1641823969. The reversal of 1641823949 is 9493281461.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1581652900 + 60171049 = 39770^2 + 7757^2 .

It is an emirp because it is prime and its reverse (9493281461) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1641823949 - 2⁴ = 1641823933 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1641823969) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 820911974 + 820911975.

It is an arithmetic number, because the mean of its divisors is an integer number (820911975).

Almost surely, 2^1641823949 is an apocalyptic number.

It is an amenable number.

1641823949 is a deficient number, since it is larger than the sum of its proper divisors (1).

1641823949 is an equidigital number, since it uses as much as digits as its factorization.

1641823949 is an evil number, because the sum of its binary digits is even.

The product of its digits is 373248, while the sum is 47.

The square root of 1641823949 is about 40519.4268098649. The cubic root of 1641823949 is about 1179.7107279524.

The spelling of 1641823949 in words is "one billion, six hundred forty-one million, eight hundred twenty-three thousand, nine hundred forty-nine".