20493905 has 8 divisors (see below), whose sum is σ = 24618600. Its totient is φ = 16377856.

The previous prime is 20493901. The next prime is 20493911. The reversal of 20493905 is 50939402.

It can be written as a sum of positive squares in 4 ways, for example, as 744769 + 19749136 = 863^2 + 4444^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20493905 - 2² = 20493901 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20493901) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5591 + ... + 8499.

It is an arithmetic number, because the mean of its divisors is an integer number (3077325).

Almost surely, 2^20493905 is an apocalyptic number.

It is an amenable number.

20493905 is a deficient number, since it is larger than the sum of its proper divisors (4124695).

20493905 is a wasteful number, since it uses less digits than its factorization.

20493905 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4323.

The product of its (nonzero) digits is 9720, while the sum is 32.

The square root of 20493905 is about 4527.0194388803. The cubic root of 20493905 is about 273.6580572921.

The spelling of 20493905 in words is "twenty million, four hundred ninety-three thousand, nine hundred five".