1020040421 has 4 divisors (see below), whose sum is σ = 1029398700. Its totient is φ = 1010682144.

The previous prime is 1020040339. The next prime is 1020040433. The reversal of 1020040421 is 1240400201.

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 388523521 + 631516900 = 19711^2 + 25130^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1020040421 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1020040396 and 1020040405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1020040451) 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, 4678976 + ... + 4679193.

It is an arithmetic number, because the mean of its divisors is an integer number (257349675).

Almost surely, 2^1020040421 is an apocalyptic number.

It is an amenable number.

1020040421 is a deficient number, since it is larger than the sum of its proper divisors (9358279).

1020040421 is an equidigital number, since it uses as much as digits as its factorization.

1020040421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9358278.

The product of its (nonzero) digits is 64, while the sum is 14.

The square root of 1020040421 is about 31938.0716543751. The cubic root of 1020040421 is about 1006.6360063441.

Adding to 1020040421 its reverse (1240400201), we get a palindrome (2260440622).

The spelling of 1020040421 in words is "one billion, twenty million, forty thousand, four hundred twenty-one".