20509542 has 24 divisors (see below), whose sum is σ = 45168240. Its totient is φ = 6724080.

The previous prime is 20509523. The next prime is 20509543. The reversal of 20509542 is 24590502.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20509543) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 8242 + ... + 10437.

It is an arithmetic number, because the mean of its divisors is an integer number (1882010).

Almost surely, 2^20509542 is an apocalyptic number.

20509542 is an abundant number, since it is smaller than the sum of its proper divisors (24658698).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20509542 is a wasteful number, since it uses less digits than its factorization.

20509542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18748 (or 18745 counting only the distinct ones).

The product of its (nonzero) digits is 3600, while the sum is 27.

The square root of 20509542 is about 4528.7461841000. The cubic root of 20509542 is about 273.7276406333.

The spelling of 20509542 in words is "twenty million, five hundred nine thousand, five hundred forty-two".