20994109 has 2 divisors, whose sum is σ = 20994110. Its totient is φ = 20994108.

The previous prime is 20994097. The next prime is 20994119. The reversal of 20994109 is 90149902.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14976900 + 6017209 = 3870^2 + 2453^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20994109 is a prime.

It is a super-2 number, since 2×20994109² = 881505225407762, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20994119) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10497054 + 10497055.

It is an arithmetic number, because the mean of its divisors is an integer number (10497055).

Almost surely, 2^20994109 is an apocalyptic number.

It is an amenable number.

20994109 is a deficient number, since it is larger than the sum of its proper divisors (1).

20994109 is an equidigital number, since it uses as much as digits as its factorization.

20994109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5832, while the sum is 34.

The square root of 20994109 is about 4581.9328890764. The cubic root of 20994109 is about 275.8666170947.

The spelling of 20994109 in words is "twenty million, nine hundred ninety-four thousand, one hundred nine".