21898429056 has 384 divisors, whose sum is σ = 76453977600. Its totient is φ = 6108576768.

The previous prime is 21898429039. The next prime is 21898429057. The reversal of 21898429056 is 65092489812.

It is a happy number.

21898429056 is a `hidden beast` number, since 218 + 98 + 4 + 290 + 56 = 666.

It is a tau number, because it is divible by the number of its divisors (384).

It is a super-2 number, since 2×21898429056² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a junction number, because it is equal to n+sod(n) for n = 21898428993 and 21898429011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21898429057) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 9361135 + ... + 9363473.

It is an arithmetic number, because the mean of its divisors is an integer number (199098900).

Almost surely, 2^21898429056 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 21898429056, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38226988800).

21898429056 is an abundant number, since it is smaller than the sum of its proper divisors (54555548544).

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

21898429056 is an equidigital number, since it uses as much as digits as its factorization.

21898429056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2418 (or 2394 counting only the distinct ones).

The product of its (nonzero) digits is 2488320, while the sum is 54.

The spelling of 21898429056 in words is "twenty-one billion, eight hundred ninety-eight million, four hundred twenty-nine thousand, fifty-six".