1551411991 has 2 divisors, whose sum is σ = 1551411992. Its totient is φ = 1551411990.

The previous prime is 1551411977. The next prime is 1551412063. The reversal of 1551411991 is 1991141551.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1551411991 - 2⁷ = 1551411863 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1551411991.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1551411931) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 775705995 + 775705996.

It is an arithmetic number, because the mean of its divisors is an integer number (775705996).

Almost surely, 2^1551411991 is an apocalyptic number.

1551411991 is a deficient number, since it is larger than the sum of its proper divisors (1).

1551411991 is an equidigital number, since it uses as much as digits as its factorization.

1551411991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 8100, while the sum is 37.

The square root of 1551411991 is about 39387.9675916389. The cubic root of 1551411991 is about 1157.6458376952.

The spelling of 1551411991 in words is "one billion, five hundred fifty-one million, four hundred eleven thousand, nine hundred ninety-one".