20261539 has 4 divisors (see below), whose sum is σ = 20282080. Its totient is φ = 20241000.

The previous prime is 20261519. The next prime is 20261567. The reversal of 20261539 is 93516202.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20261539 - 2¹³ = 20253347 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20261519) 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, 8712 + ... + 10789.

It is an arithmetic number, because the mean of its divisors is an integer number (5070520).

Almost surely, 2^20261539 is an apocalyptic number.

20261539 is a deficient number, since it is larger than the sum of its proper divisors (20541).

20261539 is a wasteful number, since it uses less digits than its factorization.

20261539 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20540.

The product of its (nonzero) digits is 3240, while the sum is 28.

The square root of 20261539 is about 4501.2819285177. The cubic root of 20261539 is about 272.6198513276.

The spelling of 20261539 in words is "twenty million, two hundred sixty-one thousand, five hundred thirty-nine".