20401689 has 72 divisors (see below), whose sum is σ = 36873984. Its totient is φ = 9979200.

The previous prime is 20401663. The next prime is 20401691. The reversal of 20401689 is 98610402.

It is not a de Polignac number, because 20401689 - 2⁷ = 20401561 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20401609) 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 71 ways as a sum of consecutive naturals, for example, 551379 + ... + 551415.

Almost surely, 2^20401689 is an apocalyptic number.

It is an amenable number.

20401689 is a deficient number, since it is larger than the sum of its proper divisors (16472295).

20401689 is a wasteful number, since it uses less digits than its factorization.

20401689 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 107 (or 89 counting only the distinct ones).

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

The square root of 20401689 is about 4516.8228878272. The cubic root of 20401689 is about 273.2469822742.

The spelling of 20401689 in words is "twenty million, four hundred one thousand, six hundred eighty-nine".