20964138 has 16 divisors (see below), whose sum is σ = 45153696. Its totient is φ = 6450480.

The previous prime is 20964137. The next prime is 20964143. The reversal of 20964138 is 83146902.

It is a super-4 number, since 4×20964138⁴ (a number of 30 digits) contains 4444 as substring. Note that it is a super-d number also for d = 3.

It is a junction number, because it is equal to n+sod(n) for n = 20964099 and 20964108.

It is not an unprimeable number, because it can be changed into a prime (20964137) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 134308 + ... + 134463.

It is an arithmetic number, because the mean of its divisors is an integer number (2822106).

Almost surely, 2^20964138 is an apocalyptic number.

20964138 is an abundant number, since it is smaller than the sum of its proper divisors (24189558).

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

20964138 is a wasteful number, since it uses less digits than its factorization.

20964138 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 268789.

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 20964138 is about 4578.6611580243. The cubic root of 20964138 is about 275.7352796809.

The spelling of 20964138 in words is "twenty million, nine hundred sixty-four thousand, one hundred thirty-eight".