538261921 has 4 divisors (see below), whose sum is σ = 540572292. Its totient is φ = 535951552.

The previous prime is 538261877. The next prime is 538261931. The reversal of 538261921 is 129162835.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 129162835 = 5 ⋅25832567.

It can be written as a sum of positive squares in 2 ways, for example, as 354794896 + 183467025 = 18836^2 + 13545^2 .

It is a cyclic number.

It is not a de Polignac number, because 538261921 - 2²³ = 529873313 is a prime.

It is a super-2 number, since 2×538261921² = 579451791197220482, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (538261931) 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, 1154836 + ... + 1155301.

It is an arithmetic number, because the mean of its divisors is an integer number (135143073).

Almost surely, 2^538261921 is an apocalyptic number.

It is an amenable number.

538261921 is a deficient number, since it is larger than the sum of its proper divisors (2310371).

538261921 is a wasteful number, since it uses less digits than its factorization.

538261921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2310370.

The product of its digits is 25920, while the sum is 37.

The square root of 538261921 is about 23200.4724305347. The cubic root of 538261921 is about 813.4506658901.

The spelling of 538261921 in words is "five hundred thirty-eight million, two hundred sixty-one thousand, nine hundred twenty-one".