20797978 has 8 divisors (see below), whose sum is σ = 31217472. Its totient is φ = 10392156.

The previous prime is 20797961. The next prime is 20797981. The reversal of 20797978 is 87979702.

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2301 + ... + 6847.

It is an arithmetic number, because the mean of its divisors is an integer number (3902184).

Almost surely, 2^20797978 is an apocalyptic number.

20797978 is a deficient number, since it is larger than the sum of its proper divisors (10419494).

20797978 is a wasteful number, since it uses less digits than its factorization.

20797978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6836.

The product of its (nonzero) digits is 444528, while the sum is 49.

The square root of 20797978 is about 4560.4800185945. The cubic root of 20797978 is about 275.0048616220.

The spelling of 20797978 in words is "twenty million, seven hundred ninety-seven thousand, nine hundred seventy-eight".