7138478521 has 16 divisors (see below), whose sum is σ = 7357115520. Its totient is φ = 6923629440.

The previous prime is 7138478507. The next prime is 7138478527. The reversal of 7138478521 is 1258748317.

It is a cyclic number.

It is not a de Polignac number, because 7138478521 - 2⁵ = 7138478489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7138478527) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2294515 + ... + 2297623.

It is an arithmetic number, because the mean of its divisors is an integer number (459819720).

Almost surely, 2^7138478521 is an apocalyptic number.

7138478521 is a gapful number since it is divisible by the number (71) formed by its first and last digit.

It is an amenable number.

7138478521 is a deficient number, since it is larger than the sum of its proper divisors (218636999).

7138478521 is a wasteful number, since it uses less digits than its factorization.

7138478521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3696.

The product of its digits is 376320, while the sum is 46.

The square root of 7138478521 is about 84489.5172255115. The cubic root of 7138478521 is about 1925.4631838476.

The spelling of 7138478521 in words is "seven billion, one hundred thirty-eight million, four hundred seventy-eight thousand, five hundred twenty-one".