20542705 has 16 divisors (see below), whose sum is σ = 26064000. Its totient is φ = 15543216.

The previous prime is 20542673. The next prime is 20542729. The reversal of 20542705 is 50724502.

It is not a de Polignac number, because 20542705 - 2⁵ = 20542673 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20542705.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33996 + ... + 34594.

It is an arithmetic number, because the mean of its divisors is an integer number (1629000).

Almost surely, 2^20542705 is an apocalyptic number.

It is an amenable number.

20542705 is a deficient number, since it is larger than the sum of its proper divisors (5521295).

20542705 is an frugal number, since it uses more digits than its factorization.

20542705 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 661 (or 623 counting only the distinct ones).

The product of its (nonzero) digits is 2800, while the sum is 25.

The square root of 20542705 is about 4532.4060938976. The cubic root of 20542705 is about 273.8750962490.

The spelling of 20542705 in words is "twenty million, five hundred forty-two thousand, seven hundred five".