20535993 has 6 divisors (see below), whose sum is σ = 29663114. Its totient is φ = 13690656.

The previous prime is 20535947. The next prime is 20536013. The reversal of 20535993 is 39953502.

It can be written as a sum of positive squares in only one way, i.e., 10969344 + 9566649 = 3312^2 + 3093^2 .

It is not a de Polignac number, because 20535993 - 2⁶ = 20535929 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20535923) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1140880 + ... + 1140897.

Almost surely, 2^20535993 is an apocalyptic number.

It is an amenable number.

20535993 is a deficient number, since it is larger than the sum of its proper divisors (9127121).

20535993 is a wasteful number, since it uses less digits than its factorization.

20535993 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2281783 (or 2281780 counting only the distinct ones).

The product of its (nonzero) digits is 36450, while the sum is 36.

The square root of 20535993 is about 4531.6655878385. The cubic root of 20535993 is about 273.8452648987.

It can be divided in two parts, 20535 and 993, that added together give a triangular number (21528 = T₂₀₇).

The spelling of 20535993 in words is "twenty million, five hundred thirty-five thousand, nine hundred ninety-three".