21002140435 has 4 divisors (see below), whose sum is σ = 25202568528. Its totient is φ = 16801712344.

The previous prime is 21002140433. The next prime is 21002140469. The reversal of 21002140435 is 53404120012.

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

It is a cyclic number.

It is not a de Polignac number, because 21002140435 - 2¹ = 21002140433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21002140433) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2100214039 + ... + 2100214048.

It is an arithmetic number, because the mean of its divisors is an integer number (6300642132).

Almost surely, 2^21002140435 is an apocalyptic number.

21002140435 is a deficient number, since it is larger than the sum of its proper divisors (4200428093).

21002140435 is an equidigital number, since it uses as much as digits as its factorization.

21002140435 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4200428092.

The product of its (nonzero) digits is 960, while the sum is 22.

Adding to 21002140435 its reverse (53404120012), we get a palindrome (74406260447).

The spelling of 21002140435 in words is "twenty-one billion, two million, one hundred forty thousand, four hundred thirty-five".