20613445 has 4 divisors (see below), whose sum is σ = 24736140. Its totient is φ = 16490752.

The previous prime is 20613433. The next prime is 20613457. The reversal of 20613445 is 54431602.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54431602 = 2 ⋅27215801.

It is an interprime number because it is at equal distance from previous prime (20613433) and next prime (20613457).

It can be written as a sum of positive squares in 2 ways, for example, as 8958049 + 11655396 = 2993^2 + 3414^2 .

It is a cyclic number.

It is not a de Polignac number, because 20613445 - 2⁵ = 20613413 is a prime.

It is a super-2 number, since 2×20613445² = 849828229536050, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2061340 + ... + 2061349.

It is an arithmetic number, because the mean of its divisors is an integer number (6184035).

Almost surely, 2^20613445 is an apocalyptic number.

It is an amenable number.

20613445 is a deficient number, since it is larger than the sum of its proper divisors (4122695).

20613445 is an equidigital number, since it uses as much as digits as its factorization.

20613445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4122694.

The product of its (nonzero) digits is 2880, while the sum is 25.

The square root of 20613445 is about 4540.2031892857. The cubic root of 20613445 is about 274.1891043660.

The spelling of 20613445 in words is "twenty million, six hundred thirteen thousand, four hundred forty-five".