1949877581 has 2 divisors, whose sum is σ = 1949877582. Its totient is φ = 1949877580.

The previous prime is 1949877569. The next prime is 1949877701. The reversal of 1949877581 is 1857789491.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1913275081 + 36602500 = 43741^2 + 6050^2 .

It is an emirp because it is prime and its reverse (1857789491) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1949877581 is a prime.

It is a super-2 number, since 2×1949877581² = 7604045161772823122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 1949877581.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1949877551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 974938790 + 974938791.

It is an arithmetic number, because the mean of its divisors is an integer number (974938791).

Almost surely, 2^1949877581 is an apocalyptic number.

It is an amenable number.

1949877581 is a deficient number, since it is larger than the sum of its proper divisors (1).

1949877581 is an equidigital number, since it uses as much as digits as its factorization.

1949877581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 5080320, while the sum is 59.

The square root of 1949877581 is about 44157.4181876613. The cubic root of 1949877581 is about 1249.3068329666.

It can be divided in two parts, 19498 and 77581, that added together give a palindrome (97079).

The spelling of 1949877581 in words is "one billion, nine hundred forty-nine million, eight hundred seventy-seven thousand, five hundred eighty-one".