20278579 has 2 divisors, whose sum is σ = 20278580. Its totient is φ = 20278578.

The previous prime is 20278549. The next prime is 20278613. The reversal of 20278579 is 97587202.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20278579 is a prime.

It is a super-2 number, since 2×20278579² = 822441532518482, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20278519) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10139289 + 10139290.

It is an arithmetic number, because the mean of its divisors is an integer number (10139290).

Almost surely, 2^20278579 is an apocalyptic number.

20278579 is a deficient number, since it is larger than the sum of its proper divisors (1).

20278579 is an equidigital number, since it uses as much as digits as its factorization.

20278579 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 70560, while the sum is 40.

The square root of 20278579 is about 4503.1743248513. The cubic root of 20278579 is about 272.6962545498.

The spelling of 20278579 in words is "twenty million, two hundred seventy-eight thousand, five hundred seventy-nine".