20849664 has 88 divisors (see below), whose sum is σ = 60722208. Its totient is φ = 6307840.

The previous prime is 20849659. The next prime is 20849677. The reversal of 20849664 is 46694802.

It is a tau number, because it is divible by the number of its divisors (88).

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33484 + ... + 34100.

Almost surely, 2^20849664 is an apocalyptic number.

20849664 is a gapful number since it is divisible by the number (24) 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 20849664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30361104).

20849664 is an abundant number, since it is smaller than the sum of its proper divisors (39872544).

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

20849664 is a wasteful number, since it uses less digits than its factorization.

20849664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 651 (or 633 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 39.

The square root of 20849664 is about 4566.1432303422. The cubic root of 20849664 is about 275.2324821944.

The spelling of 20849664 in words is "twenty million, eight hundred forty-nine thousand, six hundred sixty-four".