20645377 has 4 divisors (see below), whose sum is σ = 20681136. Its totient is φ = 20609620.

The previous prime is 20645347. The next prime is 20645399. The reversal of 20645377 is 77354602.

It is a happy number.

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 a de Polignac number, because none of the positive numbers 2^k-20645377 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20645347) 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, 16999 + ... + 18172.

It is an arithmetic number, because the mean of its divisors is an integer number (5170284).

Almost surely, 2^20645377 is an apocalyptic number.

It is an amenable number.

20645377 is a deficient number, since it is larger than the sum of its proper divisors (35759).

20645377 is an equidigital number, since it uses as much as digits as its factorization.

20645377 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35758.

The product of its (nonzero) digits is 35280, while the sum is 34.

The square root of 20645377 is about 4543.7184111694. The cubic root of 20645377 is about 274.3306121603.

Adding to 20645377 its reverse (77354602), we get a palindrome (97999979).

The spelling of 20645377 in words is "twenty million, six hundred forty-five thousand, three hundred seventy-seven".