20870869 has 2 divisors, whose sum is σ = 20870870. Its totient is φ = 20870868.

The previous prime is 20870813. The next prime is 20870879. The reversal of 20870869 is 96807802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 17766225 + 3104644 = 4215^2 + 1762^2 .

It is a cyclic number.

It is not a de Polignac number, because 20870869 - 2²¹ = 18773717 is a prime.

It is a super-2 number, since 2×20870869² = 871186345630322, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20870879) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10435434 + 10435435.

It is an arithmetic number, because the mean of its divisors is an integer number (10435435).

Almost surely, 2^20870869 is an apocalyptic number.

It is an amenable number.

20870869 is a deficient number, since it is larger than the sum of its proper divisors (1).

20870869 is an equidigital number, since it uses as much as digits as its factorization.

20870869 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 48384, while the sum is 40.

The square root of 20870869 is about 4568.4646217301. The cubic root of 20870869 is about 275.3257583149.

The spelling of 20870869 in words is "twenty million, eight hundred seventy thousand, eight hundred sixty-nine".