5191261018 has 4 divisors (see below), whose sum is σ = 7786891530. Its totient is φ = 2595630508.

The previous prime is 5191260973. The next prime is 5191261021. The reversal of 5191261018 is 8101621915.

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., 5161416649 + 29844369 = 71843^2 + 5463^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1297815253 + ... + 1297815256.

Almost surely, 2^5191261018 is an apocalyptic number.

5191261018 is a deficient number, since it is larger than the sum of its proper divisors (2595630512).

5191261018 is a wasteful number, since it uses less digits than its factorization.

5191261018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2595630511.

The product of its (nonzero) digits is 4320, while the sum is 34.

The square root of 5191261018 is about 72050.4060918466. The cubic root of 5191261018 is about 1731.5071475296.

The spelling of 5191261018 in words is "five billion, one hundred ninety-one million, two hundred sixty-one thousand, eighteen".