21169497140 has 96 divisors (see below), whose sum is σ = 52810531200. Its totient is φ = 7041323520.

The previous prime is 21169497133. The next prime is 21169497187. The reversal of 21169497140 is 4179496112.

It is a Harshad number since it is a multiple of its sum of digits (44).

It is a junction number, because it is equal to n+sod(n) for n = 21169497091 and 21169497100.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 33902 + ... + 208538.

It is an arithmetic number, because the mean of its divisors is an integer number (550109700).

Almost surely, 2^21169497140 is an apocalyptic number.

21169497140 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 21169497140, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26405265600).

21169497140 is an abundant number, since it is smaller than the sum of its proper divisors (31641034060).

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

21169497140 is a wasteful number, since it uses less digits than its factorization.

21169497140 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 174705 (or 174703 counting only the distinct ones).

The product of its (nonzero) digits is 108864, while the sum is 44.

The spelling of 21169497140 in words is "twenty-one billion, one hundred sixty-nine million, four hundred ninety-seven thousand, one hundred forty".