1554297491 has 2 divisors, whose sum is σ = 1554297492. Its totient is φ = 1554297490.

The previous prime is 1554297487. The next prime is 1554297497. The reversal of 1554297491 is 1947924551.

It is a weak prime.

It is an emirp because it is prime and its reverse (1947924551) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1554297491 - 2² = 1554297487 is a prime.

It is not a weakly prime, because it can be changed into another prime (1554297497) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 777148745 + 777148746.

It is an arithmetic number, because the mean of its divisors is an integer number (777148746).

Almost surely, 2^1554297491 is an apocalyptic number.

1554297491 is a deficient number, since it is larger than the sum of its proper divisors (1).

1554297491 is an equidigital number, since it uses as much as digits as its factorization.

1554297491 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 453600, while the sum is 47.

The square root of 1554297491 is about 39424.5797821613. The cubic root of 1554297491 is about 1158.3631021983.

The spelling of 1554297491 in words is "one billion, five hundred fifty-four million, two hundred ninety-seven thousand, four hundred ninety-one".