20979837 has 8 divisors (see below), whose sum is σ = 31081280. Its totient is φ = 13986540.

The previous prime is 20979809. The next prime is 20979877. The reversal of 20979837 is 73897902.

It is not a de Polignac number, because 20979837 - 2¹⁸ = 20717693 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20979792 and 20979801.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20979877) 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, 388489 + ... + 388542.

It is an arithmetic number, because the mean of its divisors is an integer number (3885160).

Almost surely, 2^20979837 is an apocalyptic number.

20979837 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

It is an amenable number.

20979837 is a deficient number, since it is larger than the sum of its proper divisors (10101443).

20979837 is an equidigital number, since it uses as much as digits as its factorization.

20979837 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 777040 (or 777034 counting only the distinct ones).

The product of its (nonzero) digits is 190512, while the sum is 45.

The square root of 20979837 is about 4580.3752029719. The cubic root of 20979837 is about 275.8040906519.

The spelling of 20979837 in words is "twenty million, nine hundred seventy-nine thousand, eight hundred thirty-seven".