20587531 has 2 divisors, whose sum is σ = 20587532. Its totient is φ = 20587530.

The previous prime is 20587517. The next prime is 20587543. The reversal of 20587531 is 13578502.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20587531 - 2⁹ = 20587019 is a prime.

It is a super-2 number, since 2×20587531² = 847692865351922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 20587493 and 20587502.

It is not a weakly prime, because it can be changed into another prime (20587631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10293765 + 10293766.

It is an arithmetic number, because the mean of its divisors is an integer number (10293766).

Almost surely, 2^20587531 is an apocalyptic number.

20587531 is a deficient number, since it is larger than the sum of its proper divisors (1).

20587531 is an equidigital number, since it uses as much as digits as its factorization.

20587531 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8400, while the sum is 31.

The square root of 20587531 is about 4537.3484547696. The cubic root of 20587531 is about 274.0741580934.

The spelling of 20587531 in words is "twenty million, five hundred eighty-seven thousand, five hundred thirty-one".