21487964900 has 72 divisors (see below), whose sum is σ = 47648903400. Its totient is φ = 8408125440.

The previous prime is 21487964879. The next prime is 21487964941. The reversal of 21487964900 is 946978412.

It can be written as a sum of positive squares in 12 ways, for example, as 2922267364 + 18565697536 = 54058^2 + 136256^2 .

It is a Harshad number since it is a multiple of its sum of digits (50).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1843892 + ... + 1855508.

It is an arithmetic number, because the mean of its divisors is an integer number (661790325).

Almost surely, 2^21487964900 is an apocalyptic number.

21487964900 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 21487964900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23824451700).

21487964900 is an abundant number, since it is smaller than the sum of its proper divisors (26160938500).

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

21487964900 is a wasteful number, since it uses less digits than its factorization.

21487964900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12033 (or 12026 counting only the distinct ones).

The product of its (nonzero) digits is 870912, while the sum is 50.

The spelling of 21487964900 in words is "twenty-one billion, four hundred eighty-seven million, nine hundred sixty-four thousand, nine hundred".