1002120421 has 4 divisors (see below), whose sum is σ = 1015848172. Its totient is φ = 988392672.

The previous prime is 1002120397. The next prime is 1002120463. The reversal of 1002120421 is 1240212001.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 845995396 + 156125025 = 29086^2 + 12495^2 .

It is a cyclic number.

It is not a de Polignac number, because 1002120421 - 2⁵ = 1002120389 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1002120121) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6863766 + ... + 6863911.

It is an arithmetic number, because the mean of its divisors is an integer number (253962043).

Almost surely, 2^1002120421 is an apocalyptic number.

It is an amenable number.

1002120421 is a deficient number, since it is larger than the sum of its proper divisors (13727751).

1002120421 is an equidigital number, since it uses as much as digits as its factorization.

1002120421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13727750.

The product of its (nonzero) digits is 32, while the sum is 13.

The square root of 1002120421 is about 31656.2856475614. The cubic root of 1002120421 is about 1000.7063080115.

Adding to 1002120421 its reverse (1240212001), we get a palindrome (2242332422).

The spelling of 1002120421 in words is "one billion, two million, one hundred twenty thousand, four hundred twenty-one".