20078521 has 2 divisors, whose sum is σ = 20078522. Its totient is φ = 20078520.

The previous prime is 20078507. The next prime is 20078533. The reversal of 20078521 is 12587002.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17935225 + 2143296 = 4235^2 + 1464^2 .

It is a cyclic number.

It is not a de Polignac number, because 20078521 - 2⁷ = 20078393 is a prime.

It is not a weakly prime, because it can be changed into another prime (20078551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10039260 + 10039261.

It is an arithmetic number, because the mean of its divisors is an integer number (10039261).

Almost surely, 2^20078521 is an apocalyptic number.

It is an amenable number.

20078521 is a deficient number, since it is larger than the sum of its proper divisors (1).

20078521 is an equidigital number, since it uses as much as digits as its factorization.

20078521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1120, while the sum is 25.

The square root of 20078521 is about 4480.9062699414. The cubic root of 20078521 is about 271.7965290950.

The spelling of 20078521 in words is "twenty million, seventy-eight thousand, five hundred twenty-one".