20870156647 has 2 divisors, whose sum is σ = 20870156648. Its totient is φ = 20870156646.

The previous prime is 20870156639. The next prime is 20870156669. The reversal of 20870156647 is 74665107802.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20870156647 - 2³ = 20870156639 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 20870156597 and 20870156606.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20870156677) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10435078323 + 10435078324.

It is an arithmetic number, because the mean of its divisors is an integer number (10435078324).

Almost surely, 2^20870156647 is an apocalyptic number.

20870156647 is a deficient number, since it is larger than the sum of its proper divisors (1).

20870156647 is an equidigital number, since it uses as much as digits as its factorization.

20870156647 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 564480, while the sum is 46.

The spelling of 20870156647 in words is "twenty billion, eight hundred seventy million, one hundred fifty-six thousand, six hundred forty-seven".