538666615381 has 8 divisors (see below), whose sum is σ = 570359311704. Its totient is φ = 506974632960.

The previous prime is 538666615373. The next prime is 538666615391. The reversal of 538666615381 is 183516666835.

It can be written as a sum of positive squares in 4 ways, for example, as 384884992881 + 153781622500 = 620391^2 + 392150^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 538666615381 - 2³ = 538666615373 is a prime.

It is a super-2 number, since 2×538666615381² (a number of 24 digits) 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 (538666615321) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2720461 + ... + 2911741.

It is an arithmetic number, because the mean of its divisors is an integer number (71294913963).

Almost surely, 2^538666615381 is an apocalyptic number.

It is an amenable number.

538666615381 is a deficient number, since it is larger than the sum of its proper divisors (31692696323).

538666615381 is a wasteful number, since it uses less digits than its factorization.

538666615381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 356951.

The product of its digits is 18662400, while the sum is 58.

The spelling of 538666615381 in words is "five hundred thirty-eight billion, six hundred sixty-six million, six hundred fifteen thousand, three hundred eighty-one".