20561319 has 12 divisors (see below), whose sum is σ = 30724200. Its totient is φ = 13234704.

The previous prime is 20561311. The next prime is 20561327. The reversal of 20561319 is 91316502.

It is an interprime number because it is at equal distance from previous prime (20561311) and next prime (20561327).

It is not a de Polignac number, because 20561319 - 2³ = 20561311 is a prime.

It is a super-2 number, since 2×20561319² = 845535678039522, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20561292 and 20561301.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20561311) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 39129 + ... + 39650.

It is an arithmetic number, because the mean of its divisors is an integer number (2560350).

Almost surely, 2^20561319 is an apocalyptic number.

20561319 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

20561319 is a deficient number, since it is larger than the sum of its proper divisors (10162881).

20561319 is a wasteful number, since it uses less digits than its factorization.

20561319 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 78814 (or 78811 counting only the distinct ones).

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

The square root of 20561319 is about 4534.4590636591. The cubic root of 20561319 is about 273.9577918183.

It can be divided in two parts, 2056 and 1319, that added together give a cube (3375 = 15³).

The spelling of 20561319 in words is "twenty million, five hundred sixty-one thousand, three hundred nineteen".