21010140421 has 16 divisors (see below), whose sum is σ = 22987554624. Its totient is φ = 19121681664.

The previous prime is 21010140419. The next prime is 21010140427. The reversal of 21010140421 is 12404101012.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21010140421 - 2¹ = 21010140419 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21010140395 and 21010140404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21010140427) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 66 + ... + 204988.

It is an arithmetic number, because the mean of its divisors is an integer number (1436722164).

Almost surely, 2^21010140421 is an apocalyptic number.

It is an amenable number.

21010140421 is a deficient number, since it is larger than the sum of its proper divisors (1977414203).

21010140421 is a wasteful number, since it uses less digits than its factorization.

21010140421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 205140.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21010140421 its reverse (12404101012), we get a palindrome (33414241433).

The spelling of 21010140421 in words is "twenty-one billion, ten million, one hundred forty thousand, four hundred twenty-one".