139667881 has 2 divisors, whose sum is σ = 139667882. Its totient is φ = 139667880.

The previous prime is 139667839. The next prime is 139667939. The reversal of 139667881 is 188766931.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 111408025 + 28259856 = 10555^2 + 5316^2 .

It is a cyclic number.

It is not a de Polignac number, because 139667881 - 2¹⁵ = 139635113 is a prime.

It is a super-2 number, since 2×139667881² = 39014233966060322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (139667821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69833940 + 69833941.

It is an arithmetic number, because the mean of its divisors is an integer number (69833941).

Almost surely, 2^139667881 is an apocalyptic number.

It is an amenable number.

139667881 is a deficient number, since it is larger than the sum of its proper divisors (1).

139667881 is an equidigital number, since it uses as much as digits as its factorization.

139667881 is an evil number, because the sum of its binary digits is even.

The product of its digits is 435456, while the sum is 49.

The square root of 139667881 is about 11818.1166435266. The cubic root of 139667881 is about 518.8384836532.

The spelling of 139667881 in words is "one hundred thirty-nine million, six hundred sixty-seven thousand, eight hundred eighty-one".