20978413 has 8 divisors (see below), whose sum is σ = 22795520. Its totient is φ = 19232640.

The previous prime is 20978411. The next prime is 20978431. The reversal of 20978413 is 31487902.

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 20978413 - 2¹ = 20978411 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 (20978411) 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 in 7 ways as a sum of consecutive naturals, for example, 17220 + ... + 18397.

It is an arithmetic number, because the mean of its divisors is an integer number (2849440).

Almost surely, 2^20978413 is an apocalyptic number.

It is an amenable number.

20978413 is a deficient number, since it is larger than the sum of its proper divisors (1817107).

20978413 is a wasteful number, since it uses less digits than its factorization.

20978413 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35667.

The product of its (nonzero) digits is 12096, while the sum is 34.

The square root of 20978413 is about 4580.2197545533. The cubic root of 20978413 is about 275.7978504713.

The spelling of 20978413 in words is "twenty million, nine hundred seventy-eight thousand, four hundred thirteen".