20531745 has 32 divisors (see below), whose sum is σ = 39312000. Its totient is φ = 10107072.

The previous prime is 20531743. The next prime is 20531747. The reversal of 20531745 is 54713502.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20531743) and next prime (20531747).

It is not a de Polignac number, because 20531745 - 2¹ = 20531743 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (20531741) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4095 + ... + 7604.

It is an arithmetic number, because the mean of its divisors is an integer number (1228500).

Almost surely, 2^20531745 is an apocalyptic number.

It is an amenable number.

20531745 is a deficient number, since it is larger than the sum of its proper divisors (18780255).

20531745 is a wasteful number, since it uses less digits than its factorization.

20531745 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11726 (or 11720 counting only the distinct ones).

The product of its (nonzero) digits is 4200, while the sum is 27.

The square root of 20531745 is about 4531.1968617574. The cubic root of 20531745 is about 273.8263813884.

The spelling of 20531745 in words is "twenty million, five hundred thirty-one thousand, seven hundred forty-five".