1520421 has 12 divisors (see below), whose sum is σ = 2358432. Its totient is φ = 868728.

The previous prime is 1520417. The next prime is 1520423. The reversal of 1520421 is 1240251.

It is not a de Polignac number, because 1520421 - 2² = 1520417 is a prime.

1520421 is a lucky number.

It is a self number, because there is not a number n which added to its sum of digits gives 1520421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1520423) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 5025 + ... + 5318.

It is an arithmetic number, because the mean of its divisors is an integer number (196536).

2^1520421 is an apocalyptic number.

It is an amenable number.

1520421 is a deficient number, since it is larger than the sum of its proper divisors (838011).

1520421 is a wasteful number, since it uses less digits than its factorization.

1520421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10360 (or 10353 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 15.

The square root of 1520421 is about 1233.0535268187. The cubic root of 1520421 is about 114.9885558870.

Adding to 1520421 its reverse (1240251), we get a palindrome (2760672).

It can be divided in two parts, 15204 and 21, that added together give a triangular number (15225 = T₁₇₄).

The spelling of 1520421 in words is "one million, five hundred twenty thousand, four hundred twenty-one".