538508691 has 24 divisors (see below), whose sum is σ = 894123360. Its totient is φ = 305934336.

The previous prime is 538508689. The next prime is 538508699. The reversal of 538508691 is 196805835.

538508691 is a `hidden beast` number, since 53 + 8 + 508 + 6 + 91 = 666.

It is not a de Polignac number, because 538508691 - 2¹ = 538508689 is a prime.

It is a super-2 number, since 2×538508691² = 579983220565066962, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (538508699) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13806 + ... + 35603.

It is an arithmetic number, because the mean of its divisors is an integer number (37255140).

Almost surely, 2^538508691 is an apocalyptic number.

538508691 is a deficient number, since it is larger than the sum of its proper divisors (355614669).

538508691 is a wasteful number, since it uses less digits than its factorization.

538508691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 49595 (or 49592 counting only the distinct ones).

The product of its (nonzero) digits is 259200, while the sum is 45.

The square root of 538508691 is about 23205.7900318003. The cubic root of 538508691 is about 813.5749576427.

The spelling of 538508691 in words is "five hundred thirty-eight million, five hundred eight thousand, six hundred ninety-one".