20449969 has 2 divisors, whose sum is σ = 20449970. Its totient is φ = 20449968.

The previous prime is 20449951. The next prime is 20449973. The reversal of 20449969 is 96994402.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 18662400 + 1787569 = 4320^2 + 1337^2 .

It is a cyclic number.

It is not a de Polignac number, because 20449969 - 2¹⁷ = 20318897 is a prime.

It is a super-2 number, since 2×20449969² = 836402464201922, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20449999) by changing a digit.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10224984 + 10224985.

It is an arithmetic number, because the mean of its divisors is an integer number (10224985).

Almost surely, 2^20449969 is an apocalyptic number.

It is an amenable number.

20449969 is a deficient number, since it is larger than the sum of its proper divisors (1).

20449969 is an equidigital number, since it uses as much as digits as its factorization.

20449969 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 139968, while the sum is 43.

The square root of 20449969 is about 4522.1641942769. The cubic root of 20449969 is about 273.4623561339.

The spelling of 20449969 in words is "twenty million, four hundred forty-nine thousand, nine hundred sixty-nine".