1550195891 has 2 divisors, whose sum is σ = 1550195892. Its totient is φ = 1550195890.

The previous prime is 1550195869. The next prime is 1550195917. The reversal of 1550195891 is 1985910551.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1550195891 - 2¹⁸ = 1549933747 is a prime.

It is not a weakly prime, because it can be changed into another prime (1550195861) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 775097945 + 775097946.

It is an arithmetic number, because the mean of its divisors is an integer number (775097946).

Almost surely, 2^1550195891 is an apocalyptic number.

1550195891 is a deficient number, since it is larger than the sum of its proper divisors (1).

1550195891 is an equidigital number, since it uses as much as digits as its factorization.

1550195891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 81000, while the sum is 44.

The square root of 1550195891 is about 39372.5271096484. The cubic root of 1550195891 is about 1157.3432786678.

The spelling of 1550195891 in words is "one billion, five hundred fifty million, one hundred ninety-five thousand, eight hundred ninety-one".