872491993 has 4 divisors (see below), whose sum is σ = 900636928. Its totient is φ = 844347060.

The previous prime is 872491957. The next prime is 872492021. The reversal of 872491993 is 399194278.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 872491993 - 2¹⁷ = 872360921 is a prime.

It is a super-3 number, since 3×872491993³ (a number of 28 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 872491993.

It is not an unprimeable number, because it can be changed into a prime (872491943) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14072421 + ... + 14072482.

It is an arithmetic number, because the mean of its divisors is an integer number (225159232).

Almost surely, 2^872491993 is an apocalyptic number.

It is an amenable number.

872491993 is a deficient number, since it is larger than the sum of its proper divisors (28144935).

872491993 is a wasteful number, since it uses less digits than its factorization.

872491993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28144934.

The product of its digits is 979776, while the sum is 52.

The square root of 872491993 is about 29537.9754384081. The cubic root of 872491993 is about 955.5508797805.

The spelling of 872491993 in words is "eight hundred seventy-two million, four hundred ninety-one thousand, nine hundred ninety-three".