1520421431 has 4 divisors (see below), whose sum is σ = 1522566600. Its totient is φ = 1518276264.

The previous prime is 1520421421. The next prime is 1520421433. The reversal of 1520421431 is 1341240251.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1341240251 = 13 ⋅103172327.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1520421431 is a prime.

It is a super-2 number, since 2×1520421431² = 4623362655688175522, 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 = 1520421397 and 1520421406.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1520421433) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1071521 + ... + 1072938.

It is an arithmetic number, because the mean of its divisors is an integer number (380641650).

Almost surely, 2^1520421431 is an apocalyptic number.

1520421431 is a deficient number, since it is larger than the sum of its proper divisors (2145169).

1520421431 is an equidigital number, since it uses as much as digits as its factorization.

1520421431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2145168.

The product of its (nonzero) digits is 960, while the sum is 23.

The square root of 1520421431 is about 38992.5817431983. The cubic root of 1520421431 is about 1149.8856675245.

Adding to 1520421431 its reverse (1341240251), we get a palindrome (2861661682).

The spelling of 1520421431 in words is "one billion, five hundred twenty million, four hundred twenty-one thousand, four hundred thirty-one".