21670601640 has 128 divisors (see below), whose sum is σ = 67033612800. Its totient is φ = 5601173760.

The previous prime is 21670601629. The next prime is 21670601671. The reversal of 21670601640 is 4610607612.

It is a super-2 number, since 2×21670601640² (a number of 21 digits) contains 22 as substring.

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, 659931 + ... + 691989.

It is an arithmetic number, because the mean of its divisors is an integer number (523700100).

Almost surely, 2^21670601640 is an apocalyptic number.

21670601640 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 21670601640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33516806400).

21670601640 is an abundant number, since it is smaller than the sum of its proper divisors (45363011160).

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

21670601640 is a wasteful number, since it uses less digits than its factorization.

21670601640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32247 (or 32243 counting only the distinct ones).

The product of its (nonzero) digits is 12096, while the sum is 33.

The spelling of 21670601640 in words is "twenty-one billion, six hundred seventy million, six hundred one thousand, six hundred forty".