1540997947 has 2 divisors, whose sum is σ = 1540997948. Its totient is φ = 1540997946.

The previous prime is 1540997903. The next prime is 1540997951. The reversal of 1540997947 is 7497990451.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1540997947 is a prime.

It is not a weakly prime, because it can be changed into another prime (1540997347) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 770498973 + 770498974.

It is an arithmetic number, because the mean of its divisors is an integer number (770498974).

Almost surely, 2^1540997947 is an apocalyptic number.

1540997947 is a deficient number, since it is larger than the sum of its proper divisors (1).

1540997947 is an equidigital number, since it uses as much as digits as its factorization.

1540997947 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2857680, while the sum is 55.

The square root of 1540997947 is about 39255.5467036188. The cubic root of 1540997947 is about 1155.0497400542.

The spelling of 1540997947 in words is "one billion, five hundred forty million, nine hundred ninety-seven thousand, nine hundred forty-seven".