1551099491 has 2 divisors, whose sum is σ = 1551099492. Its totient is φ = 1551099490.

The previous prime is 1551099467. The next prime is 1551099527. The reversal of 1551099491 is 1949901551.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 1551099491 - 2¹⁰ = 1551098467 is a prime.

It is not a weakly prime, because it can be changed into another prime (1551099391) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 775549745 + 775549746.

It is an arithmetic number, because the mean of its divisors is an integer number (775549746).

Almost surely, 2^1551099491 is an apocalyptic number.

1551099491 is a deficient number, since it is larger than the sum of its proper divisors (1).

1551099491 is an equidigital number, since it uses as much as digits as its factorization.

1551099491 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 72900, while the sum is 44.

The square root of 1551099491 is about 39384.0004443429. Note that the first 3 decimals coincide. The cubic root of 1551099491 is about 1157.5681045035.

The spelling of 1551099491 in words is "one billion, five hundred fifty-one million, ninety-nine thousand, four hundred ninety-one".