20619943 has 2 divisors, whose sum is σ = 20619944. Its totient is φ = 20619942.

The previous prime is 20619931. The next prime is 20619979. The reversal of 20619943 is 34991602.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20619943 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20619899 and 20619908.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20619043) 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 as a sum of consecutive naturals, namely, 10309971 + 10309972.

It is an arithmetic number, because the mean of its divisors is an integer number (10309972).

Almost surely, 2^20619943 is an apocalyptic number.

20619943 is a deficient number, since it is larger than the sum of its proper divisors (1).

20619943 is an equidigital number, since it uses as much as digits as its factorization.

20619943 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11664, while the sum is 34.

The square root of 20619943 is about 4540.9187396385. The cubic root of 20619943 is about 274.2179123215.

The spelling of 20619943 in words is "twenty million, six hundred nineteen thousand, nine hundred forty-three".