20689425 has 60 divisors (see below), whose sum is σ = 40645836. Its totient is φ = 10368000.

The previous prime is 20689411. The next prime is 20689439. The reversal of 20689425 is 52498602.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20689411) and next prime (20689439).

It can be written as a sum of positive squares in 6 ways, for example, as 762129 + 19927296 = 873^2 + 4464^2 .

It is not a de Polignac number, because 20689425 - 2⁵ = 20689393 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 20689425.

It is an unprimeable number.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 34125 + ... + 34725.

Almost surely, 2^20689425 is an apocalyptic number.

20689425 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20689425 is a deficient number, since it is larger than the sum of its proper divisors (19956411).

20689425 is a wasteful number, since it uses less digits than its factorization.

20689425 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 640 (or 626 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 36.

The square root of 20689425 is about 4548.5629598808. The cubic root of 20689425 is about 274.5255731796.

The spelling of 20689425 in words is "twenty million, six hundred eighty-nine thousand, four hundred twenty-five".