139784969 has 2 divisors, whose sum is σ = 139784970. Its totient is φ = 139784968.

The previous prime is 139784947. The next prime is 139784971. The reversal of 139784969 is 969487931.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 116359369 + 23425600 = 10787^2 + 4840^2 .

It is an emirp because it is prime and its reverse (969487931) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 139784969 - 2¹² = 139780873 is a prime.

It is a super-2 number, since 2×139784969² = 39079675116661922, which contains 22 as substring.

Together with 139784971, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (139784069) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69892484 + 69892485.

It is an arithmetic number, because the mean of its divisors is an integer number (69892485).

Almost surely, 2^139784969 is an apocalyptic number.

It is an amenable number.

139784969 is a deficient number, since it is larger than the sum of its proper divisors (1).

139784969 is an equidigital number, since it uses as much as digits as its factorization.

139784969 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2939328, while the sum is 56.

The square root of 139784969 is about 11823.0693561359. The cubic root of 139784969 is about 518.9834293909.

The spelling of 139784969 in words is "one hundred thirty-nine million, seven hundred eighty-four thousand, nine hundred sixty-nine".