20661467 has 4 divisors (see below), whose sum is σ = 21051360. Its totient is φ = 20271576.

The previous prime is 20661463. The next prime is 20661523. The reversal of 20661467 is 76416602.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 76416602 = 2 ⋅38208301.

It is a cyclic number.

It is not a de Polignac number, because 20661467 - 2² = 20661463 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20661463) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 194867 + ... + 194972.

It is an arithmetic number, because the mean of its divisors is an integer number (5262840).

Almost surely, 2^20661467 is an apocalyptic number.

20661467 is a deficient number, since it is larger than the sum of its proper divisors (389893).

20661467 is an equidigital number, since it uses as much as digits as its factorization.

20661467 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 389892.

The product of its (nonzero) digits is 12096, while the sum is 32.

The square root of 20661467 is about 4545.4886425994. The cubic root of 20661467 is about 274.4018602879.

The spelling of 20661467 in words is "twenty million, six hundred sixty-one thousand, four hundred sixty-seven".