1540436491 has 4 divisors (see below), whose sum is σ = 1680476184. Its totient is φ = 1400396800.

The previous prime is 1540436489. The next prime is 1540436497. The reversal of 1540436491 is 1946340451.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1946340451 = 11 ⋅176940041.

It is not a de Polignac number, because 1540436491 - 2¹ = 1540436489 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1540436491.

It is not an unprimeable number, because it can be changed into a prime (1540436497) 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, 70019830 + ... + 70019851.

It is an arithmetic number, because the mean of its divisors is an integer number (420119046).

Almost surely, 2^1540436491 is an apocalyptic number.

1540436491 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

1540436491 is a deficient number, since it is larger than the sum of its proper divisors (140039693).

1540436491 is a wasteful number, since it uses less digits than its factorization.

1540436491 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 140039692.

The product of its (nonzero) digits is 51840, while the sum is 37.

The square root of 1540436491 is about 39248.3947569834. The cubic root of 1540436491 is about 1154.9094438726.

The spelling of 1540436491 in words is "one billion, five hundred forty million, four hundred thirty-six thousand, four hundred ninety-one".