21421520000 has 160 divisors (see below), whose sum is σ = 54776387820. Its totient is φ = 8335872000.

The previous prime is 21421519981. The next prime is 21421520023. The reversal of 21421520000 is 2512412.

It can be written as a sum of positive squares in 10 ways, for example, as 14318656 + 21407201344 = 3784^2 + 146312^2 .

It is a tau number, because it is divible by the number of its divisors (160).

It is a super-2 number, since 2×21421520000² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 2956382 + ... + 2963618.

Almost surely, 2^21421520000 is an apocalyptic number.

21421520000 is a gapful number since it is divisible by the number (20) 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 21421520000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27388193910).

21421520000 is an abundant number, since it is smaller than the sum of its proper divisors (33354867820).

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

21421520000 is an frugal number, since it uses more digits than its factorization.

21421520000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7308 (or 7281 counting only the distinct ones).

The product of its (nonzero) digits is 160, while the sum is 17.

The spelling of 21421520000 in words is "twenty-one billion, four hundred twenty-one million, five hundred twenty thousand".