521025431 has 4 divisors (see below), whose sum is σ = 521093664. Its totient is φ = 520957200.

The previous prime is 521025419. The next prime is 521025443. The reversal of 521025431 is 134520125.

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

It is an interprime number because it is at equal distance from previous prime (521025419) and next prime (521025443).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-521025431 is a prime.

It is a super-2 number, since 2×521025431² = 542934999497471522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 521025397 and 521025406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (521025331) 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, 20975 + ... + 38496.

It is an arithmetic number, because the mean of its divisors is an integer number (130273416).

Almost surely, 2^521025431 is an apocalyptic number.

521025431 is a deficient number, since it is larger than the sum of its proper divisors (68233).

521025431 is an equidigital number, since it uses as much as digits as its factorization.

521025431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68232.

The product of its (nonzero) digits is 1200, while the sum is 23.

The square root of 521025431 is about 22825.9814903982. The cubic root of 521025431 is about 804.6733914171.

Adding to 521025431 its reverse (134520125), we get a palindrome (655545556).

The spelling of 521025431 in words is "five hundred twenty-one million, twenty-five thousand, four hundred thirty-one".