20601551 has 4 divisors (see below), whose sum is σ = 20674632. Its totient is φ = 20528472.

The previous prime is 20601547. The next prime is 20601593. The reversal of 20601551 is 15510602.

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 20601551 - 2² = 20601547 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20601851) 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, 36116 + ... + 36681.

It is an arithmetic number, because the mean of its divisors is an integer number (5168658).

Almost surely, 2^20601551 is an apocalyptic number.

20601551 is a deficient number, since it is larger than the sum of its proper divisors (73081).

20601551 is an equidigital number, since it uses as much as digits as its factorization.

20601551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73080.

The product of its (nonzero) digits is 300, while the sum is 20.

The square root of 20601551 is about 4538.8931470128. The cubic root of 20601551 is about 274.1363583281.

The spelling of 20601551 in words is "twenty million, six hundred one thousand, five hundred fifty-one".