21106160640 has 264 divisors, whose sum is σ = 76984558560. Its totient is φ = 5331861504.

The previous prime is 21106160639. The next prime is 21106160681. The reversal of 21106160640 is 4606160112.

21106160640 is a `hidden beast` number, since 2 + 1 + 1 + 0 + 6 + 16 + 0 + 640 = 666.

It is a super-2 number, since 2×21106160640² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

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, 863467 + ... + 887573.

Almost surely, 2^21106160640 is an apocalyptic number.

21106160640 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 21106160640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (38492279280).

21106160640 is an abundant number, since it is smaller than the sum of its proper divisors (55878397920).

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

21106160640 is a wasteful number, since it uses less digits than its factorization.

21106160640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24157 (or 24136 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The spelling of 21106160640 in words is "twenty-one billion, one hundred six million, one hundred sixty thousand, six hundred forty".