20978411 has 2 divisors, whose sum is σ = 20978412. Its totient is φ = 20978410.

The previous prime is 20978401. The next prime is 20978431. The reversal of 20978411 is 11487902.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20978411 - 2²² = 16784107 is a prime.

It is not a weakly prime, because it can be changed into another prime (20978401) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10489205 + 10489206.

It is an arithmetic number, because the mean of its divisors is an integer number (10489206).

Almost surely, 2^20978411 is an apocalyptic number.

20978411 is a deficient number, since it is larger than the sum of its proper divisors (1).

20978411 is an equidigital number, since it uses as much as digits as its factorization.

20978411 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 4032, while the sum is 32.

The square root of 20978411 is about 4580.2195362231. The cubic root of 20978411 is about 275.7978417068.

The spelling of 20978411 in words is "twenty million, nine hundred seventy-eight thousand, four hundred eleven".