20328551 has 8 divisors (see below), whose sum is σ = 20900880. Its totient is φ = 19760832.

The previous prime is 20328547. The next prime is 20328557. The reversal of 20328551 is 15582302.

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 20328551 - 2² = 20328547 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20328551.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20328557) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9005 + ... + 11033.

It is an arithmetic number, because the mean of its divisors is an integer number (2612610).

Almost surely, 2^20328551 is an apocalyptic number.

20328551 is a deficient number, since it is larger than the sum of its proper divisors (572329).

20328551 is a wasteful number, since it uses less digits than its factorization.

20328551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2305.

The product of its (nonzero) digits is 2400, while the sum is 26.

The square root of 20328551 is about 4508.7194412605. The cubic root of 20328551 is about 272.9200703445.

The spelling of 20328551 in words is "twenty million, three hundred twenty-eight thousand, five hundred fifty-one".