20531465 has 4 divisors (see below), whose sum is σ = 24637764. Its totient is φ = 16425168.

The previous prime is 20531437. The next prime is 20531477. The reversal of 20531465 is 56413502.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56413502 = 2 ⋅28206751.

It can be written as a sum of positive squares in 2 ways, for example, as 4338889 + 16192576 = 2083^2 + 4024^2 .

It is a cyclic number.

It is not a de Polignac number, because 20531465 - 2²⁰ = 19482889 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2053142 + ... + 2053151.

It is an arithmetic number, because the mean of its divisors is an integer number (6159441).

Almost surely, 2^20531465 is an apocalyptic number.

It is an amenable number.

20531465 is a deficient number, since it is larger than the sum of its proper divisors (4106299).

20531465 is an equidigital number, since it uses as much as digits as its factorization.

20531465 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4106298.

The product of its (nonzero) digits is 3600, while the sum is 26.

The square root of 20531465 is about 4531.1659647380. The cubic root of 20531465 is about 273.8251366211.

Adding to 20531465 its reverse (56413502), we get a palindrome (76944967).

It can be divided in two parts, 205314 and 65, that added together give a cube (205379 = 59³).

The spelling of 20531465 in words is "twenty million, five hundred thirty-one thousand, four hundred sixty-five".