20853678465408 has 128 divisors (see below), whose sum is σ = 55633200973920. Its totient is φ = 6921081962496.

The previous prime is 20853678465349. The next prime is 20853678465409. The reversal of 20853678465408 is 80456487635802.

It is a tau number, because it is divible by the number of its divisors (128).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20853678465409) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 105309466 + ... + 105507302.

Almost surely, 2^{20853678465408} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20853678465408, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27816600486960).

20853678465408 is an abundant number, since it is smaller than the sum of its proper divisors (34779522508512).

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

20853678465408 is a wasteful number, since it uses less digits than its factorization.

20853678465408 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 199044 (or 199032 counting only the distinct ones).

The product of its (nonzero) digits is 309657600, while the sum is 66.

The spelling of 20853678465408 in words is "twenty trillion, eight hundred fifty-three billion, six hundred seventy-eight million, four hundred sixty-five thousand, four hundred eight".