1516391638 has 4 divisors (see below), whose sum is σ = 2274587460. Its totient is φ = 758195818.

The previous prime is 1516391623. The next prime is 1516391663. The reversal of 1516391638 is 8361936151.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 8361936151 = 6653 ⋅1256867.

It is a junction number, because it is equal to n+sod(n) for n = 1516391594 and 1516391603.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 379097908 + ... + 379097911.

It is an arithmetic number, because the mean of its divisors is an integer number (568646865).

Almost surely, 2^1516391638 is an apocalyptic number.

1516391638 is a deficient number, since it is larger than the sum of its proper divisors (758195822).

1516391638 is an equidigital number, since it uses as much as digits as its factorization.

1516391638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 758195821.

The product of its digits is 116640, while the sum is 43.

The square root of 1516391638 is about 38940.8736162917. The cubic root of 1516391638 is about 1148.8688658588.

The spelling of 1516391638 in words is "one billion, five hundred sixteen million, three hundred ninety-one thousand, six hundred thirty-eight".