20905542 has 48 divisors (see below), whose sum is σ = 52416000. Its totient is φ = 5898096.

The previous prime is 20905519. The next prime is 20905559. The reversal of 20905542 is 24550902.

20905542 is a `hidden beast` number, since 20 + 90 + 554 + 2 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 9459 + ... + 11457.

It is an arithmetic number, because the mean of its divisors is an integer number (1092000).

Almost surely, 2^20905542 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 20905542, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26208000).

20905542 is an abundant number, since it is smaller than the sum of its proper divisors (31510458).

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

20905542 is a wasteful number, since it uses less digits than its factorization.

20905542 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2097 (or 2094 counting only the distinct ones).

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

The square root of 20905542 is about 4572.2578667437. The cubic root of 20905542 is about 275.4781411792.

The spelling of 20905542 in words is "twenty million, nine hundred five thousand, five hundred forty-two".