20720427 has 32 divisors (see below), whose sum is σ = 34513920. Its totient is φ = 10765440.

The previous prime is 20720423. The next prime is 20720429. The reversal of 20720427 is 72402702.

It is not a de Polignac number, because 20720427 - 2² = 20720423 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20720397 and 20720406.

It is not an unprimeable number, because it can be changed into a prime (20720423) 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 31 ways as a sum of consecutive naturals, for example, 18849 + ... + 19917.

It is an arithmetic number, because the mean of its divisors is an integer number (1078560).

Almost surely, 2^20720427 is an apocalyptic number.

20720427 is a deficient number, since it is larger than the sum of its proper divisors (13793493).

20720427 is a wasteful number, since it uses less digits than its factorization.

20720427 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1163.

The product of its (nonzero) digits is 1568, while the sum is 24.

The square root of 20720427 is about 4551.9695737120. The cubic root of 20720427 is about 274.6626253909.

The spelling of 20720427 in words is "twenty million, seven hundred twenty thousand, four hundred twenty-seven".