20641577 has 4 divisors (see below), whose sum is σ = 22518096. Its totient is φ = 18765060.

The previous prime is 20641571. The next prime is 20641589. The reversal of 20641577 is 77514602.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20641577 - 2⁶ = 20641513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20641571) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 938243 + ... + 938264.

It is an arithmetic number, because the mean of its divisors is an integer number (5629524).

Almost surely, 2^20641577 is an apocalyptic number.

It is an amenable number.

20641577 is a deficient number, since it is larger than the sum of its proper divisors (1876519).

20641577 is a wasteful number, since it uses less digits than its factorization.

20641577 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1876518.

The product of its (nonzero) digits is 11760, while the sum is 32.

The square root of 20641577 is about 4543.3002322101. The cubic root of 20641577 is about 274.3137799773.

The spelling of 20641577 in words is "twenty million, six hundred forty-one thousand, five hundred seventy-seven".