20623549 has 4 divisors (see below), whose sum is σ = 20710080. Its totient is φ = 20537020.

The previous prime is 20623513. The next prime is 20623573. The reversal of 20623549 is 94532602.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 20623549 - 2¹⁷ = 20492477 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20623549.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20623579) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 42907 + ... + 43384.

It is an arithmetic number, because the mean of its divisors is an integer number (5177520).

Almost surely, 2^20623549 is an apocalyptic number.

It is an amenable number.

20623549 is a deficient number, since it is larger than the sum of its proper divisors (86531).

20623549 is an equidigital number, since it uses as much as digits as its factorization.

20623549 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86530.

The product of its (nonzero) digits is 12960, while the sum is 31.

The square root of 20623549 is about 4541.3157784942. The cubic root of 20623549 is about 274.2338963966.

The spelling of 20623549 in words is "twenty million, six hundred twenty-three thousand, five hundred forty-nine".