1581873242 has 4 divisors (see below), whose sum is σ = 2372809866. Its totient is φ = 790936620.

The previous prime is 1581873233. The next prime is 1581873257. The reversal of 1581873242 is 2423781851.

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

It can be written as a sum of positive squares in only one way, i.e., 1515467041 + 66406201 = 38929^2 + 8149^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1581873242.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 395468309 + ... + 395468312.

Almost surely, 2^1581873242 is an apocalyptic number.

1581873242 is a deficient number, since it is larger than the sum of its proper divisors (790936624).

1581873242 is an equidigital number, since it uses as much as digits as its factorization.

1581873242 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 790936623.

The product of its digits is 107520, while the sum is 41.

The square root of 1581873242 is about 39772.7701071977. The cubic root of 1581873242 is about 1165.1733959399.

The spelling of 1581873242 in words is "one billion, five hundred eighty-one million, eight hundred seventy-three thousand, two hundred forty-two".