139268781 has 8 divisors (see below), whose sum is σ = 206324160. Its totient is φ = 92845836.

The previous prime is 139268761. The next prime is 139268807. The reversal of 139268781 is 187862931.

It is not a de Polignac number, because 139268781 - 2⁷ = 139268653 is a prime.

It is a super-2 number, since 2×139268781² = 38791586722451922, which contains 22 as substring.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (139268711) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2579025 + ... + 2579078.

It is an arithmetic number, because the mean of its divisors is an integer number (25790520).

Almost surely, 2^139268781 is an apocalyptic number.

It is an amenable number.

139268781 is a deficient number, since it is larger than the sum of its proper divisors (67055379).

139268781 is an equidigital number, since it uses as much as digits as its factorization.

139268781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5158112 (or 5158106 counting only the distinct ones).

The product of its digits is 145152, while the sum is 45.

The square root of 139268781 is about 11801.2194708852. The cubic root of 139268781 is about 518.3438197327.

The spelling of 139268781 in words is "one hundred thirty-nine million, two hundred sixty-eight thousand, seven hundred eighty-one".