20591613 has 36 divisors (see below), whose sum is σ = 35292348. Its totient is φ = 11531520.

The previous prime is 20591609. The next prime is 20591617. The reversal of 20591613 is 31619502.

It is an interprime number because it is at equal distance from previous prime (20591609) and next prime (20591617).

It can be written as a sum of positive squares in 2 ways, for example, as 9018009 + 11573604 = 3003^2 + 3402^2 .

It is not a de Polignac number, because 20591613 - 2² = 20591609 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20591617) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 22933 + ... + 23813.

It is an arithmetic number, because the mean of its divisors is an integer number (980343).

Almost surely, 2^20591613 is an apocalyptic number.

It is an amenable number.

20591613 is a deficient number, since it is larger than the sum of its proper divisors (14700735).

20591613 is a wasteful number, since it uses less digits than its factorization.

20591613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 954 (or 944 counting only the distinct ones).

The product of its (nonzero) digits is 1620, while the sum is 27.

The square root of 20591613 is about 4537.7982546605. The cubic root of 20591613 is about 274.0922709466.

The spelling of 20591613 in words is "twenty million, five hundred ninety-one thousand, six hundred thirteen".