20978701 has 2 divisors, whose sum is σ = 20978702. Its totient is φ = 20978700.

The previous prime is 20978681. The next prime is 20978719. The reversal of 20978701 is 10787902.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15093225 + 5885476 = 3885^2 + 2426^2 .

It is a cyclic number.

It is not a de Polignac number, because 20978701 - 2⁵ = 20978669 is a prime.

It is equal to p_1328668 and since 20978701 and 1328668 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20978761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10489350 + 10489351.

It is an arithmetic number, because the mean of its divisors is an integer number (10489351).

Almost surely, 2^20978701 is an apocalyptic number.

It is an amenable number.

20978701 is a deficient number, since it is larger than the sum of its proper divisors (1).

20978701 is an equidigital number, since it uses as much as digits as its factorization.

20978701 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7056, while the sum is 34.

The square root of 20978701 is about 4580.2511939849. The cubic root of 20978701 is about 275.7991125531.

The spelling of 20978701 in words is "twenty million, nine hundred seventy-eight thousand, seven hundred one".