20691465 has 32 divisors (see below), whose sum is σ = 35738496. Its totient is φ = 10183680.

The previous prime is 20691457. The next prime is 20691469. The reversal of 20691465 is 56419602.

It is not a de Polignac number, because 20691465 - 2³ = 20691457 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20691469) 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 31 ways as a sum of consecutive naturals, for example, 12750 + ... + 14280.

It is an arithmetic number, because the mean of its divisors is an integer number (1116828).

Almost surely, 2^20691465 is an apocalyptic number.

It is an amenable number.

20691465 is a deficient number, since it is larger than the sum of its proper divisors (15047031).

20691465 is a wasteful number, since it uses less digits than its factorization.

20691465 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1609.

The product of its (nonzero) digits is 12960, while the sum is 33.

The square root of 20691465 is about 4548.7872010020. The cubic root of 20691465 is about 274.5345957239.

The spelling of 20691465 in words is "twenty million, six hundred ninety-one thousand, four hundred sixty-five".