20661725 has 24 divisors (see below), whose sum is σ = 30081408. Its totient is φ = 13780800.

The previous prime is 20661703. The next prime is 20661727. The reversal of 20661725 is 52716602.

It is not a de Polignac number, because 20661725 - 2¹⁰ = 20660701 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20661727) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4880 + ... + 8070.

It is an arithmetic number, because the mean of its divisors is an integer number (1253392).

Almost surely, 2^20661725 is an apocalyptic number.

20661725 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

It is an amenable number.

20661725 is a deficient number, since it is larger than the sum of its proper divisors (9419683).

20661725 is a wasteful number, since it uses less digits than its factorization.

20661725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3245 (or 3240 counting only the distinct ones).

The product of its (nonzero) digits is 5040, while the sum is 29.

The square root of 20661725 is about 4545.5170222979. The cubic root of 20661725 is about 274.4030024364.

The spelling of 20661725 in words is "twenty million, six hundred sixty-one thousand, seven hundred twenty-five".