20505995 has 24 divisors (see below), whose sum is σ = 27320544. Its totient is φ = 14744576.

The previous prime is 20505983. The next prime is 20506001. The reversal of 20505995 is 59950502.

It is not a de Polignac number, because 20505995 - 2¹⁴ = 20489611 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 23 ways as a sum of consecutive naturals, for example, 32927 + ... + 33543.

It is an arithmetic number, because the mean of its divisors is an integer number (1138356).

Almost surely, 2^20505995 is an apocalyptic number.

20505995 is a deficient number, since it is larger than the sum of its proper divisors (6814549).

20505995 is a wasteful number, since it uses less digits than its factorization.

20505995 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 679 (or 662 counting only the distinct ones).

The product of its (nonzero) digits is 20250, while the sum is 35.

The square root of 20505995 is about 4528.3545576732. The cubic root of 20505995 is about 273.7118598824.

The spelling of 20505995 in words is "twenty million, five hundred five thousand, nine hundred ninety-five".