825139531 has 4 divisors (see below), whose sum is σ = 825620152. Its totient is φ = 824658912.

The previous prime is 825139519. The next prime is 825139537. The reversal of 825139531 is 135931528.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 825139531 - 2⁹ = 825139019 is a prime.

It is a super-2 number, since 2×825139531² = 1361710491237799922, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (825139537) 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, 237726 + ... + 241171.

It is an arithmetic number, because the mean of its divisors is an integer number (206405038).

Almost surely, 2^825139531 is an apocalyptic number.

825139531 is a deficient number, since it is larger than the sum of its proper divisors (480621).

825139531 is a wasteful number, since it uses less digits than its factorization.

825139531 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 480620.

The product of its digits is 32400, while the sum is 37.

The square root of 825139531 is about 28725.2420529401. The cubic root of 825139531 is about 937.9415992694.

The spelling of 825139531 in words is "eight hundred twenty-five million, one hundred thirty-nine thousand, five hundred thirty-one".