21187714740 has 72 divisors (see below), whose sum is σ = 59696286048. Its totient is φ = 5614971840.

The previous prime is 21187714711. The next prime is 21187714741. The reversal of 21187714740 is 4741778112.

It is a super-2 number, since 2×21187714740² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21187714692 and 21187714701.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21187714741) 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, 1587495 + ... + 1600785.

It is an arithmetic number, because the mean of its divisors is an integer number (829115084).

Almost surely, 2^21187714740 is an apocalyptic number.

21187714740 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 21187714740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29848143024).

21187714740 is an abundant number, since it is smaller than the sum of its proper divisors (38508571308).

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

21187714740 is a wasteful number, since it uses less digits than its factorization.

21187714740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13629 (or 13464 counting only the distinct ones).

The product of its (nonzero) digits is 87808, while the sum is 42.

The spelling of 21187714740 in words is "twenty-one billion, one hundred eighty-seven million, seven hundred fourteen thousand, seven hundred forty".