20980917 has 8 divisors (see below), whose sum is σ = 31082880. Its totient is φ = 13987260.

The previous prime is 20980913. The next prime is 20980919. The reversal of 20980917 is 71908902.

It is a happy number.

It is not a de Polignac number, because 20980917 - 2² = 20980913 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20980913) 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, 388509 + ... + 388562.

It is an arithmetic number, because the mean of its divisors is an integer number (3885360).

Almost surely, 2^20980917 is an apocalyptic number.

20980917 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

20980917 is a deficient number, since it is larger than the sum of its proper divisors (10101963).

20980917 is an equidigital number, since it uses as much as digits as its factorization.

20980917 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 777080 (or 777074 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 36.

The square root of 20980917 is about 4580.4930957267. The cubic root of 20980917 is about 275.8088231848.

The spelling of 20980917 in words is "twenty million, nine hundred eighty thousand, nine hundred seventeen".