1540456397 has 2 divisors, whose sum is σ = 1540456398. Its totient is φ = 1540456396.

The previous prime is 1540456367. The next prime is 1540456403. The reversal of 1540456397 is 7936540451.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 978813796 + 561642601 = 31286^2 + 23699^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1540456397 is a prime.

It is a super-2 number, since 2×1540456397² = 4746011822116443218, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1540456367) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 770228198 + 770228199.

It is an arithmetic number, because the mean of its divisors is an integer number (770228199).

Almost surely, 2^1540456397 is an apocalyptic number.

It is an amenable number.

1540456397 is a deficient number, since it is larger than the sum of its proper divisors (1).

1540456397 is an equidigital number, since it uses as much as digits as its factorization.

1540456397 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 453600, while the sum is 44.

The square root of 1540456397 is about 39248.6483461533. The cubic root of 1540456397 is about 1154.9144185510.

The spelling of 1540456397 in words is "one billion, five hundred forty million, four hundred fifty-six thousand, three hundred ninety-seven".