75515772000421 has 4 divisors (see below), whose sum is σ = 75516270839500. Its totient is φ = 75515273161344.

The previous prime is 75515772000373. The next prime is 75515772000443. The reversal of 75515772000421 is 12400027751557.

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 10621243950625 + 64894528049796 = 3259025^2 + 8055714^2 .

It is a cyclic number.

It is not a de Polignac number, because 75515772000421 - 2⁹ = 75515771999909 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 (75515772000481) 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, 249192396 + ... + 249495253.

It is an arithmetic number, because the mean of its divisors is an integer number (18879067709875).

Almost surely, 2^{75515772000421} is an apocalyptic number.

It is an amenable number.

75515772000421 is a deficient number, since it is larger than the sum of its proper divisors (498839079).

75515772000421 is a wasteful number, since it uses less digits than its factorization.

75515772000421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 498839078.

The product of its (nonzero) digits is 686000, while the sum is 46.

Adding to 75515772000421 its reverse (12400027751557), we get a palindrome (87915799751978).

The spelling of 75515772000421 in words is "seventy-five trillion, five hundred fifteen billion, seven hundred seventy-two million, four hundred twenty-one", and thus it is an aban number.