20431275 has 12 divisors (see below), whose sum is σ = 33779832. Its totient is φ = 10896640.

The previous prime is 20431273. The next prime is 20431277. The reversal of 20431275 is 57213402.

It is an interprime number because it is at equal distance from previous prime (20431273) and next prime (20431277).

It is not a de Polignac number, because 20431275 - 2¹ = 20431273 is a prime.

It is not an unprimeable number, because it can be changed into a prime (20431273) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 136134 + ... + 136283.

It is an arithmetic number, because the mean of its divisors is an integer number (2814986).

Almost surely, 2^20431275 is an apocalyptic number.

20431275 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

20431275 is a deficient number, since it is larger than the sum of its proper divisors (13348557).

20431275 is a wasteful number, since it uses less digits than its factorization.

20431275 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 272430 (or 272425 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 24.

The square root of 20431275 is about 4520.0967909991. The cubic root of 20431275 is about 273.3790037045.

Adding to 20431275 its reverse (57213402), we get a palindrome (77644677).

It can be divided in two parts, 20431 and 275, that added together give a triangular number (20706 = T₂₀₃).

The spelling of 20431275 in words is "twenty million, four hundred thirty-one thousand, two hundred seventy-five".