20606821747 has 8 divisors (see below), whose sum is σ = 20905391520. Its totient is φ = 20309741760.

The previous prime is 20606821727. The next prime is 20606821801. The reversal of 20606821747 is 74712860602.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20606821747 is a prime.

It is a super-2 number, since 2×20606821747² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20606821727) 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, 344568 + ... + 399925.

It is an arithmetic number, because the mean of its divisors is an integer number (2613173940).

Almost surely, 2^20606821747 is an apocalyptic number.

20606821747 is a deficient number, since it is larger than the sum of its proper divisors (298569773).

20606821747 is an equidigital number, since it uses as much as digits as its factorization.

20606821747 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 744893.

The product of its (nonzero) digits is 225792, while the sum is 43.

The spelling of 20606821747 in words is "twenty billion, six hundred six million, eight hundred twenty-one thousand, seven hundred forty-seven".