1540522554521 has 4 divisors (see below), whose sum is σ = 1540720242612. Its totient is φ = 1540324866432.

The previous prime is 1540522554491. The next prime is 1540522554533. The reversal of 1540522554521 is 1254552250451.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 777904596121 + 762617958400 = 881989^2 + 873280^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1540522554521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1540522584521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 98832356 + ... + 98847941.

It is an arithmetic number, because the mean of its divisors is an integer number (385180060653).

Almost surely, 2^{1540522554521} is an apocalyptic number.

It is an amenable number.

1540522554521 is a deficient number, since it is larger than the sum of its proper divisors (197688091).

1540522554521 is an equidigital number, since it uses as much as digits as its factorization.

1540522554521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 197688090.

The product of its (nonzero) digits is 400000, while the sum is 41.

The spelling of 1540522554521 in words is "one trillion, five hundred forty billion, five hundred twenty-two million, five hundred fifty-four thousand, five hundred twenty-one".