20721187471 has 8 divisors (see below), whose sum is σ = 20839682864. Its totient is φ = 20602961280.

The previous prime is 20721187469. The next prime is 20721187499. The reversal of 20721187471 is 17478112702.

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

It is a cyclic number.

It is not a de Polignac number, because 20721187471 - 2¹ = 20721187469 is a prime.

It is a super-3 number, since 3×20721187471³ (a number of 32 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20721107471) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 88105 + ... + 221821.

It is an arithmetic number, because the mean of its divisors is an integer number (2604960358).

Almost surely, 2^20721187471 is an apocalyptic number.

20721187471 is a deficient number, since it is larger than the sum of its proper divisors (118495393).

20721187471 is a wasteful number, since it uses less digits than its factorization.

20721187471 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 134601.

The product of its (nonzero) digits is 43904, while the sum is 40.

The spelling of 20721187471 in words is "twenty billion, seven hundred twenty-one million, one hundred eighty-seven thousand, four hundred seventy-one".