21421431416 has 64 divisors (see below), whose sum is σ = 50328000000. Its totient is φ = 8304024960.

The previous prime is 21421431413. The next prime is 21421431433. The reversal of 21421431416 is 61413412412.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21421431413) 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, 35210 + ... + 209958.

It is an arithmetic number, because the mean of its divisors is an integer number (786375000).

Almost surely, 2^21421431416 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21421431416, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25164000000).

21421431416 is an abundant number, since it is smaller than the sum of its proper divisors (28906568584).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21421431416 is a wasteful number, since it uses less digits than its factorization.

21421431416 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 174972 (or 174968 counting only the distinct ones).

The product of its digits is 4608, while the sum is 29.

Adding to 21421431416 its reverse (61413412412), we get a palindrome (82834843828).

The spelling of 21421431416 in words is "twenty-one billion, four hundred twenty-one million, four hundred thirty-one thousand, four hundred sixteen".