7525815381 has 30 divisors (see below), whose sum is σ = 13077746550. Its totient is φ = 4300463664.

The previous prime is 7525815371. The next prime is 7525815413. The reversal of 7525815381 is 1835185257.

7525815381 is a `hidden beast` number, since 7 + 5 + 258 + 15 + 381 = 666.

It can be written as a sum of positive squares in only one way, i.e., 5479700625 + 2046114756 = 74025^2 + 45234^2 .

It is not a de Polignac number, because 7525815381 - 2¹¹ = 7525813333 is a prime.

It is a super-2 number, since 2×7525815381² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7525815301) by changing a digit.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 944106 + ... + 952043.

It is an arithmetic number, because the mean of its divisors is an integer number (435924885).

Almost surely, 2^7525815381 is an apocalyptic number.

It is an amenable number.

7525815381 is a deficient number, since it is larger than the sum of its proper divisors (5551931169).

7525815381 is a wasteful number, since it uses less digits than its factorization.

7525815381 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1896175 (or 1896159 counting only the distinct ones).

The product of its digits is 336000, while the sum is 45.

The square root of 7525815381 is about 86751.4575151334. The cubic root of 7525815381 is about 1959.6771109260.

The spelling of 7525815381 in words is "seven billion, five hundred twenty-five million, eight hundred fifteen thousand, three hundred eighty-one".