538407225661 has 4 divisors (see below), whose sum is σ = 539585360092. Its totient is φ = 537229091232.

The previous prime is 538407225649. The next prime is 538407225667. The reversal of 538407225661 is 166522704835.

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

It can be written as a sum of positive squares in 2 ways, for example, as 442690622500 + 95716603161 = 665350^2 + 309381^2 .

It is a cyclic number.

It is not a de Polignac number, because 538407225661 - 2¹⁹ = 538406701373 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 (538407225667) 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, 589066530 + ... + 589067443.

It is an arithmetic number, because the mean of its divisors is an integer number (134896340023).

Almost surely, 2^538407225661 is an apocalyptic number.

It is an amenable number.

538407225661 is a deficient number, since it is larger than the sum of its proper divisors (1178134431).

538407225661 is a wasteful number, since it uses less digits than its factorization.

538407225661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1178134430.

The product of its (nonzero) digits is 2419200, while the sum is 49.

The spelling of 538407225661 in words is "five hundred thirty-eight billion, four hundred seven million, two hundred twenty-five thousand, six hundred sixty-one".