21219187500 has 504 divisors, whose sum is σ = 81387083232. Its totient is φ = 4550400000.

The previous prime is 21219187477. The next prime is 21219187531. The reversal of 21219187500 is 578191212.

It is a happy number.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 167 ways as a sum of consecutive naturals, for example, 66937342 + ... + 66937658.

It is an arithmetic number, because the mean of its divisors is an integer number (161482308).

Almost surely, 2^21219187500 is an apocalyptic number.

21219187500 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 21219187500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (40693541616).

21219187500 is an abundant number, since it is smaller than the sum of its proper divisors (60167895732).

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

21219187500 is a wasteful number, since it uses less digits than its factorization.

21219187500 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 381 (or 351 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 36.

The spelling of 21219187500 in words is "twenty-one billion, two hundred nineteen million, one hundred eighty-seven thousand, five hundred".