1540013993 has 6 divisors (see below), whose sum is σ = 1791444906. Its totient is φ = 1320011952.

The previous prime is 1540013987. The next prime is 1540014017. The reversal of 1540013993 is 3993100451.

It can be written as a sum of positive squares in only one way, i.e., 1460233369 + 79780624 = 38213^2 + 8932^2 .

It is not a de Polignac number, because 1540013993 - 2¹⁶ = 1539948457 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1540013393) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 15714380 + ... + 15714477.

It is an arithmetic number, because the mean of its divisors is an integer number (298574151).

Almost surely, 2^1540013993 is an apocalyptic number.

It is an amenable number.

1540013993 is a deficient number, since it is larger than the sum of its proper divisors (251430913).

1540013993 is an equidigital number, since it uses as much as digits as its factorization.

1540013993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31428871 (or 31428864 counting only the distinct ones).

The product of its (nonzero) digits is 14580, while the sum is 35.

The square root of 1540013993 is about 39243.0120276209. The cubic root of 1540013993 is about 1154.8038479263.

The spelling of 1540013993 in words is "one billion, five hundred forty million, thirteen thousand, nine hundred ninety-three".