20980551 has 4 divisors (see below), whose sum is σ = 27974072. Its totient is φ = 13987032.

The previous prime is 20980537. The next prime is 20980559. The reversal of 20980551 is 15508902.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 20980551 - 2⁹ = 20980039 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 (20980559) 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, 3496756 + ... + 3496761.

It is an arithmetic number, because the mean of its divisors is an integer number (6993518).

Almost surely, 2^20980551 is an apocalyptic number.

20980551 is a deficient number, since it is larger than the sum of its proper divisors (6993521).

20980551 is an equidigital number, since it uses as much as digits as its factorization.

20980551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6993520.

The product of its (nonzero) digits is 3600, while the sum is 30.

The square root of 20980551 is about 4580.4531435219. The cubic root of 20980551 is about 275.8072194001.

The spelling of 20980551 in words is "twenty million, nine hundred eighty thousand, five hundred fifty-one".