1516668381 has 10 divisors (see below), whose sum is σ = 2265640542. Its totient is φ = 1011112200.

The previous prime is 1516668359. The next prime is 1516668403. The reversal of 1516668381 is 1838666151.

It is an interprime number because it is at equal distance from previous prime (1516668359) and next prime (1516668403).

It can be written as a sum of positive squares in only one way, i.e., 1476864900 + 39803481 = 38430^2 + 6309^2 .

It is a de Polignac number, because none of the positive numbers 2^k-1516668381 is a prime.

It is a super-2 number, since 2×1516668381² = 4600565955850322322, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1516668301) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 9362070 + ... + 9362231.

Almost surely, 2^1516668381 is an apocalyptic number.

It is an amenable number.

1516668381 is a deficient number, since it is larger than the sum of its proper divisors (748972161).

1516668381 is an equidigital number, since it uses as much as digits as its factorization.

1516668381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18724313 (or 18724304 counting only the distinct ones).

The product of its digits is 207360, while the sum is 45.

The square root of 1516668381 is about 38944.4268284950. The cubic root of 1516668381 is about 1148.9387515157.

The spelling of 1516668381 in words is "one billion, five hundred sixteen million, six hundred sixty-eight thousand, three hundred eighty-one".