872491493 has 4 divisors (see below), whose sum is σ = 923814540. Its totient is φ = 821168448.

The previous prime is 872491489. The next prime is 872491507. The reversal of 872491493 is 394194278.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 394194278 = 2 ⋅197097139.

It can be written as a sum of positive squares in 2 ways, for example, as 725063329 + 147428164 = 26927^2 + 12142^2 .

It is a cyclic number.

It is not a de Polignac number, because 872491493 - 2² = 872491489 is a prime.

It is a super-2 number, since 2×872491493² = 1522482810714738098, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (872491423) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 25661498 + ... + 25661531.

It is an arithmetic number, because the mean of its divisors is an integer number (230953635).

Almost surely, 2^872491493 is an apocalyptic number.

It is an amenable number.

872491493 is a deficient number, since it is larger than the sum of its proper divisors (51323047).

872491493 is a wasteful number, since it uses less digits than its factorization.

872491493 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51323046.

The product of its digits is 435456, while the sum is 47.

The square root of 872491493 is about 29537.9669747259. The cubic root of 872491493 is about 955.5506972476.

The spelling of 872491493 in words is "eight hundred seventy-two million, four hundred ninety-one thousand, four hundred ninety-three".