20520775 has 24 divisors (see below), whose sum is σ = 28176768. Its totient is φ = 14700000.

The previous prime is 20520769. The next prime is 20520809. The reversal of 20520775 is 57702502.

It is not a de Polignac number, because 20520775 - 2³ = 20520767 is a prime.

It is a super-2 number, since 2×20520775² = 842204413201250, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19000 + ... + 20050.

It is an arithmetic number, because the mean of its divisors is an integer number (1174032).

Almost surely, 2^20520775 is an apocalyptic number.

20520775 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

20520775 is a deficient number, since it is larger than the sum of its proper divisors (7655993).

20520775 is a wasteful number, since it uses less digits than its factorization.

20520775 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1143 (or 1138 counting only the distinct ones).

The product of its (nonzero) digits is 4900, while the sum is 28.

The square root of 20520775 is about 4529.9862030695. The cubic root of 20520775 is about 273.7776047168. Note that the first 3 decimals are identical.

The spelling of 20520775 in words is "twenty million, five hundred twenty thousand, seven hundred seventy-five".