20606173840 has 120 divisors (see below), whose sum is σ = 55875890232. Its totient is φ = 7046645760.

The previous prime is 20606173817. The next prime is 20606173843. The reversal of 20606173840 is 4837160602.

It can be written as a sum of positive squares in 4 ways, for example, as 9913786624 + 10692387216 = 99568^2 + 103404^2 .

It is a super-2 number, since 2×20606173840² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 20606173840.

It is not an unprimeable number, because it can be changed into a prime (20606173843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1549620 + ... + 1562860.

Almost surely, 2^20606173840 is an apocalyptic number.

20606173840 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 20606173840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27937945116).

20606173840 is an abundant number, since it is smaller than the sum of its proper divisors (35269716392).

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

20606173840 is a wasteful number, since it uses less digits than its factorization.

20606173840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13665 (or 13652 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 37.

The spelling of 20606173840 in words is "twenty billion, six hundred six million, one hundred seventy-three thousand, eight hundred forty".