20661475 has 12 divisors (see below), whose sum is σ = 26734896. Its totient is φ = 15810080.

The previous prime is 20661463. The next prime is 20661523. The reversal of 20661475 is 57416602.

It is a happy number.

It is not a de Polignac number, because 20661475 - 2¹¹ = 20659427 is a prime.

It is a Duffinian number.

It is an unprimeable number.

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 11 ways as a sum of consecutive naturals, for example, 17392 + ... + 18541.

It is an arithmetic number, because the mean of its divisors is an integer number (2227908).

Almost surely, 2^20661475 is an apocalyptic number.

20661475 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

20661475 is a deficient number, since it is larger than the sum of its proper divisors (6073421).

20661475 is a wasteful number, since it uses less digits than its factorization.

20661475 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35966 (or 35961 counting only the distinct ones).

The product of its (nonzero) digits is 10080, while the sum is 31.

The square root of 20661475 is about 4545.4895225927. The cubic root of 20661475 is about 274.4018957035.

The spelling of 20661475 in words is "twenty million, six hundred sixty-one thousand, four hundred seventy-five".