1549741891 has 2 divisors, whose sum is σ = 1549741892. Its totient is φ = 1549741890.

The previous prime is 1549741871. The next prime is 1549741931. The reversal of 1549741891 is 1981479451.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1549741891 - 2¹⁹ = 1549217603 is a prime.

It is not a weakly prime, because it can be changed into another prime (1549741871) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 774870945 + 774870946.

It is an arithmetic number, because the mean of its divisors is an integer number (774870946).

Almost surely, 2^1549741891 is an apocalyptic number.

1549741891 is a deficient number, since it is larger than the sum of its proper divisors (1).

1549741891 is an equidigital number, since it uses as much as digits as its factorization.

1549741891 is an evil number, because the sum of its binary digits is even.

The product of its digits is 362880, while the sum is 49.

The square root of 1549741891 is about 39366.7612460055. The cubic root of 1549741891 is about 1157.2302853887.

The spelling of 1549741891 in words is "one billion, five hundred forty-nine million, seven hundred forty-one thousand, eight hundred ninety-one".