20864019 has 16 divisors (see below), whose sum is σ = 30472704. Its totient is φ = 12592800.

The previous prime is 20864009. The next prime is 20864047. The reversal of 20864019 is 91046802.

It is not a de Polignac number, because 20864019 - 2⁸ = 20863763 is a prime.

It is a super-2 number, since 2×20864019² = 870614577664722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20864009) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7777 + ... + 10109.

It is an arithmetic number, because the mean of its divisors is an integer number (1904544).

Almost surely, 2^20864019 is an apocalyptic number.

20864019 is a deficient number, since it is larger than the sum of its proper divisors (9608685).

20864019 is a wasteful number, since it uses less digits than its factorization.

20864019 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2618.

The product of its (nonzero) digits is 3456, while the sum is 30.

The square root of 20864019 is about 4567.7148553735. The cubic root of 20864019 is about 275.2956335859.

It can be divided in two parts, 2086 and 4019, that added together give a triangular number (6105 = T₁₁₀).

The spelling of 20864019 in words is "twenty million, eight hundred sixty-four thousand, nineteen".