139503781 has 2 divisors, whose sum is σ = 139503782. Its totient is φ = 139503780.

The previous prime is 139503773. The next prime is 139503821. The reversal of 139503781 is 187305931.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 139027681 + 476100 = 11791^2 + 690^2 .

It is an emirp because it is prime and its reverse (187305931) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 139503781 - 2³ = 139503773 is a prime.

It is a super-2 number, since 2×139503781² = 38922609826591922, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 139503781.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (139503731) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 69751890 + 69751891.

It is an arithmetic number, because the mean of its divisors is an integer number (69751891).

Almost surely, 2^139503781 is an apocalyptic number.

It is an amenable number.

139503781 is a deficient number, since it is larger than the sum of its proper divisors (1).

139503781 is an equidigital number, since it uses as much as digits as its factorization.

139503781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 22680, while the sum is 37.

The square root of 139503781 is about 11811.1718724265. The cubic root of 139503781 is about 518.6352043657.

The spelling of 139503781 in words is "one hundred thirty-nine million, five hundred three thousand, seven hundred eighty-one".