20720343 has 16 divisors (see below), whose sum is σ = 31643136.
Its totient is φ = 11814240.
The previous prime is 20720341. The next prime is 20720347. The reversal of 20720343 is 34302702.
It is a happy number.
It is not a de Polignac number, because 20720343 - 21 = 20720341 is a prime.
It is a super-2 number, since 2×207203432 = 858665228075298, which contains 22 as substring.
It is a Harshad number since it is a multiple of its sum of digits (21).
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (20720341) by changing a digit.
It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12958 + ... + 14468.
It is an arithmetic number, because the mean of its divisors is an integer number (1977696).
Almost surely, 220720343 is an apocalyptic number.
20720343 is a deficient number, since it is larger than the sum of its proper divisors (10922793).
20720343 is a wasteful number, since it uses less digits than its factorization.
20720343 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 2174.
The product of its (nonzero) digits is 1008, while the sum is 21.
The square root of 20720343 is about 4551.9603469275.
The cubic root of 20720343 is about 274.6622542323.
The spelling of 20720343 in words is "twenty million, seven hundred twenty thousand, three hundred forty-three".