1520135431 has 4 divisors (see below), whose sum is σ = 1520217864. Its totient is φ = 1520053000.

The previous prime is 1520135381. The next prime is 1520135447. The reversal of 1520135431 is 1345310251.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 1345310251 = 107 ⋅12572993.

It is a cyclic number.

It is not a de Polignac number, because 1520135431 - 2¹⁷ = 1520004359 is a prime.

It is a super-2 number, since 2×1520135431² = 4621623457163111522, 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 = 1520135396 and 1520135405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1520135131) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 561 + ... + 55141.

It is an arithmetic number, because the mean of its divisors is an integer number (380054466).

Almost surely, 2^1520135431 is an apocalyptic number.

1520135431 is a deficient number, since it is larger than the sum of its proper divisors (82433).

1520135431 is an equidigital number, since it uses as much as digits as its factorization.

1520135431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82432.

The product of its (nonzero) digits is 1800, while the sum is 25.

The square root of 1520135431 is about 38988.9142064767. The cubic root of 1520135431 is about 1149.8135629713.

Adding to 1520135431 its reverse (1345310251), we get a palindrome (2865445682).

The spelling of 1520135431 in words is "one billion, five hundred twenty million, one hundred thirty-five thousand, four hundred thirty-one".