1520012021 has 4 divisors (see below), whose sum is σ = 1658194944. Its totient is φ = 1381829100.

The previous prime is 1520011991. The next prime is 1520012029. The reversal of 1520012021 is 1202100251.

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 1520012021 - 2⁶ = 1520011957 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1520011987 and 1520012005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1520012029) 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, 69091445 + ... + 69091466.

It is an arithmetic number, because the mean of its divisors is an integer number (414548736).

Almost surely, 2^1520012021 is an apocalyptic number.

1520012021 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1520012021 is a deficient number, since it is larger than the sum of its proper divisors (138182923).

1520012021 is a wasteful number, since it uses less digits than its factorization.

1520012021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138182922.

The product of its (nonzero) digits is 40, while the sum is 14.

The square root of 1520012021 is about 38987.3315450032. The cubic root of 1520012021 is about 1149.7824468113.

Adding to 1520012021 its reverse (1202100251), we get a palindrome (2722112272).

The spelling of 1520012021 in words is "one billion, five hundred twenty million, twelve thousand, twenty-one".