21164169240 has 160 divisors (see below), whose sum is σ = 71230531680. Its totient is φ = 5636210688.

The previous prime is 21164169239. The next prime is 21164169259. The reversal of 21164169240 is 4296146112.

21164169240 is a `hidden beast` number, since 2 + 1 + 1 + 641 + 6 + 9 + 2 + 4 + 0 = 666.

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

It is a junction number, because it is equal to n+sod(n) for n = 21164169195 and 21164169204.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 2662552 + ... + 2670488.

It is an arithmetic number, because the mean of its divisors is an integer number (445190823).

Almost surely, 2^21164169240 is an apocalyptic number.

21164169240 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 21164169240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35615265840).

21164169240 is an abundant number, since it is smaller than the sum of its proper divisors (50066362440).

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

21164169240 is a wasteful number, since it uses less digits than its factorization.

21164169240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8783 (or 8770 counting only the distinct ones).

The product of its (nonzero) digits is 20736, while the sum is 36.

The spelling of 21164169240 in words is "twenty-one billion, one hundred sixty-four million, one hundred sixty-nine thousand, two hundred forty".