21416661552 has 120 divisors (see below), whose sum is σ = 65356227648. Its totient is φ = 5990649600.

The previous prime is 21416661551. The next prime is 21416661587. The reversal of 21416661552 is 25516661412.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a self number, because there is not a number n which added to its sum of digits gives 21416661552.

It is not an unprimeable number, because it can be changed into a prime (21416661551) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 30774 + ... + 209237.

Almost surely, 2^21416661552 is an apocalyptic number.

21416661552 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21416661552, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32678113824).

21416661552 is an abundant number, since it is smaller than the sum of its proper divisors (43939566096).

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

21416661552 is a wasteful number, since it uses less digits than its factorization.

21416661552 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 240059 (or 240040 counting only the distinct ones).

The product of its digits is 86400, while the sum is 39.

The spelling of 21416661552 in words is "twenty-one billion, four hundred sixteen million, six hundred sixty-one thousand, five hundred fifty-two".