1520540421 has 8 divisors (see below), whose sum is σ = 2092786944. Its totient is φ = 980993760.

The previous prime is 1520540377. The next prime is 1520540459. The reversal of 1520540421 is 1240450251.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-1520540421 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1520540391 and 1520540400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1520540471) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8174856 + ... + 8175041.

It is an arithmetic number, because the mean of its divisors is an integer number (261598368).

Almost surely, 2^1520540421 is an apocalyptic number.

It is an amenable number.

1520540421 is a deficient number, since it is larger than the sum of its proper divisors (572246523).

1520540421 is a wasteful number, since it uses less digits than its factorization.

1520540421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16349931.

The product of its (nonzero) digits is 1600, while the sum is 24.

The square root of 1520540421 is about 38994.1075163928. The cubic root of 1520540421 is about 1149.9156638846.

Adding to 1520540421 its reverse (1240450251), we get a palindrome (2760990672).

The spelling of 1520540421 in words is "one billion, five hundred twenty million, five hundred forty thousand, four hundred twenty-one".