20993655 has 8 divisors (see below), whose sum is σ = 33589872. Its totient is φ = 11196608.

The previous prime is 20993633. The next prime is 20993663. The reversal of 20993655 is 55639902.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20993655 - 2⁶ = 20993591 is a prime.

It is a congruent number.

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, 699774 + ... + 699803.

It is an arithmetic number, because the mean of its divisors is an integer number (4198734).

Almost surely, 2^20993655 is an apocalyptic number.

20993655 is a deficient number, since it is larger than the sum of its proper divisors (12596217).

20993655 is a wasteful number, since it uses less digits than its factorization.

20993655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1399585.

The product of its (nonzero) digits is 72900, while the sum is 39.

The square root of 20993655 is about 4581.8833463981. The cubic root of 20993655 is about 275.8646285314.

The spelling of 20993655 in words is "twenty million, nine hundred ninety-three thousand, six hundred fifty-five".