20729473 has 4 divisors (see below), whose sum is σ = 21080880. Its totient is φ = 20378068.

The previous prime is 20729419. The next prime is 20729479. The reversal of 20729473 is 37492702.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20729473 - 2¹⁷ = 20598401 is a prime.

It is a super-2 number, since 2×20729473² = 859422101715458, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20729479) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 175615 + ... + 175732.

It is an arithmetic number, because the mean of its divisors is an integer number (5270220).

Almost surely, 2^20729473 is an apocalyptic number.

It is an amenable number.

20729473 is a deficient number, since it is larger than the sum of its proper divisors (351407).

20729473 is an equidigital number, since it uses as much as digits as its factorization.

20729473 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 351406.

The product of its (nonzero) digits is 21168, while the sum is 34.

The square root of 20729473 is about 4552.9631011024. The cubic root of 20729473 is about 274.7025897640.

The spelling of 20729473 in words is "twenty million, seven hundred twenty-nine thousand, four hundred seventy-three".