20661429 has 16 divisors (see below), whose sum is σ = 29526912. Its totient is φ = 12817728.

The previous prime is 20661419. The next prime is 20661437. The reversal of 20661429 is 92416602.

It is not a de Polignac number, because 20661429 - 2⁵ = 20661397 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20661396 and 20661405.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20661419) 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, 1494 + ... + 6599.

It is an arithmetic number, because the mean of its divisors is an integer number (1845432).

Almost surely, 2^20661429 is an apocalyptic number.

It is an amenable number.

20661429 is a deficient number, since it is larger than the sum of its proper divisors (8865483).

20661429 is a wasteful number, since it uses less digits than its factorization.

20661429 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8156.

The product of its (nonzero) digits is 5184, while the sum is 30.

The square root of 20661429 is about 4545.4844626288. The cubic root of 20661429 is about 274.4016920637.

The spelling of 20661429 in words is "twenty million, six hundred sixty-one thousand, four hundred twenty-nine".