1581326667 has 6 divisors (see below), whose sum is σ = 2284138532. Its totient is φ = 1054217772.

The previous prime is 1581326639. The next prime is 1581326693. The reversal of 1581326667 is 7666231851.

It is not a de Polignac number, because 1581326667 - 2²⁴ = 1564549451 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1581326867) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 87851473 + ... + 87851490.

Almost surely, 2^1581326667 is an apocalyptic number.

1581326667 is a deficient number, since it is larger than the sum of its proper divisors (702811865).

1581326667 is a wasteful number, since it uses less digits than its factorization.

1581326667 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 175702969 (or 175702966 counting only the distinct ones).

The product of its digits is 362880, while the sum is 45.

The square root of 1581326667 is about 39765.8982923811. The cubic root of 1581326667 is about 1165.0391820649.

The spelling of 1581326667 in words is "one billion, five hundred eighty-one million, three hundred twenty-six thousand, six hundred sixty-seven".