537801991 has 4 divisors (see below), whose sum is σ = 543844800. Its totient is φ = 531759184.

The previous prime is 537801983. The next prime is 537801997. The reversal of 537801991 is 199108735.

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

It is a cyclic number.

It is not a de Polignac number, because 537801991 - 2³ = 537801983 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (537801997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3021271 + ... + 3021448.

It is an arithmetic number, because the mean of its divisors is an integer number (135961200).

Almost surely, 2^537801991 is an apocalyptic number.

537801991 is a deficient number, since it is larger than the sum of its proper divisors (6042809).

537801991 is an equidigital number, since it uses as much as digits as its factorization.

537801991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6042808.

The product of its (nonzero) digits is 68040, while the sum is 43.

The square root of 537801991 is about 23190.5582295899. The cubic root of 537801991 is about 813.2189094644.

The spelling of 537801991 in words is "five hundred thirty-seven million, eight hundred one thousand, nine hundred ninety-one".