20870156669 has 2 divisors, whose sum is σ = 20870156670. Its totient is φ = 20870156668.

The previous prime is 20870156647. The next prime is 20870156677. The reversal of 20870156669 is 96665107802.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10514041444 + 10356115225 = 102538^2 + 101765^2 .

It is a cyclic number.

It is not a de Polignac number, because 20870156669 - 2⁸ = 20870156413 is a prime.

It is a super-2 number, since 2×20870156669² (a number of 21 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20870156639) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10435078334 + 10435078335.

It is an arithmetic number, because the mean of its divisors is an integer number (10435078335).

Almost surely, 2^20870156669 is an apocalyptic number.

It is an amenable number.

20870156669 is a deficient number, since it is larger than the sum of its proper divisors (1).

20870156669 is an equidigital number, since it uses as much as digits as its factorization.

20870156669 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1088640, while the sum is 50.

The spelling of 20870156669 in words is "twenty billion, eight hundred seventy million, one hundred fifty-six thousand, six hundred sixty-nine".