1520200421 has 4 divisors (see below), whose sum is σ = 1520377152. Its totient is φ = 1520023692.

The previous prime is 1520200391. The next prime is 1520200427. The reversal of 1520200421 is 1240020251.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1520200421 - 2¹⁴ = 1520184037 is a prime.

It is a super-2 number, since 2×1520200421² = 4622018640017154482, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1520200421.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1520200427) 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, 74765 + ... + 92898.

It is an arithmetic number, because the mean of its divisors is an integer number (380094288).

Almost surely, 2^1520200421 is an apocalyptic number.

It is an amenable number.

1520200421 is a deficient number, since it is larger than the sum of its proper divisors (176731).

1520200421 is an equidigital number, since it uses as much as digits as its factorization.

1520200421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 176730.

The product of its (nonzero) digits is 160, while the sum is 17.

The square root of 1520200421 is about 38989.7476396039. The cubic root of 1520200421 is about 1149.8299486426.

Adding to 1520200421 its reverse (1240020251), we get a palindrome (2760220672).

The spelling of 1520200421 in words is "one billion, five hundred twenty million, two hundred thousand, four hundred twenty-one".