20456513 has 16 divisors (see below), whose sum is σ = 26386560. Its totient is φ = 15388800.

The previous prime is 20456509. The next prime is 20456537. The reversal of 20456513 is 31565402.

It is not a de Polignac number, because 20456513 - 2² = 20456509 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20456543) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2348 + ... + 6813.

It is an arithmetic number, because the mean of its divisors is an integer number (1649160).

Almost surely, 2^20456513 is an apocalyptic number.

It is an amenable number.

20456513 is a deficient number, since it is larger than the sum of its proper divisors (5930047).

20456513 is a wasteful number, since it uses less digits than its factorization.

20456513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9208.

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

The square root of 20456513 is about 4522.8876837702. The cubic root of 20456513 is about 273.4915223853.

Subtracting 20456513 from its reverse (31565402), we obtain a square (11108889 = 3333²).

It can be divided in two parts, 2045 and 6513, that added together give a palindrome (8558).

The spelling of 20456513 in words is "twenty million, four hundred fifty-six thousand, five hundred thirteen".