21242122398 has 160 divisors (see below), whose sum is σ = 57973977600. Its totient is φ = 5749080624.

The previous prime is 21242122381. The next prime is 21242122409. The reversal of 21242122398 is 89322124212.

It is a happy number.

21242122398 is a `hidden beast` number, since 2 + 1 + 2 + 421 + 223 + 9 + 8 = 666.

It is a super-2 number, since 2×21242122398² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 2459115 + ... + 2467737.

It is an arithmetic number, because the mean of its divisors is an integer number (362337360).

Almost surely, 2^21242122398 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21242122398, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28986988800).

21242122398 is an abundant number, since it is smaller than the sum of its proper divisors (36731855202).

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

21242122398 is an equidigital number, since it uses as much as digits as its factorization.

21242122398 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8681 (or 8654 counting only the distinct ones).

The product of its digits is 27648, while the sum is 36.

The spelling of 21242122398 in words is "twenty-one billion, two hundred forty-two million, one hundred twenty-two thousand, three hundred ninety-eight".