20355666 has 16 divisors (see below), whose sum is σ = 40793088. Its totient is φ = 6771600.

The previous prime is 20355637. The next prime is 20355689. The reversal of 20355666 is 66655302.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 111 + ... + 6381.

It is an arithmetic number, because the mean of its divisors is an integer number (2549568).

Almost surely, 2^20355666 is an apocalyptic number.

20355666 is an abundant number, since it is smaller than the sum of its proper divisors (20437422).

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

20355666 is a wasteful number, since it uses less digits than its factorization.

20355666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6817.

The product of its (nonzero) digits is 32400, while the sum is 33.

The square root of 20355666 is about 4511.7253905795. The cubic root of 20355666 is about 273.0413601815.

The spelling of 20355666 in words is "twenty million, three hundred fifty-five thousand, six hundred sixty-six".