139688761 has 9 divisors (see below), whose sum is σ = 143015439. Its totient is φ = 136438536.

The previous prime is 139688749. The next prime is 139688767. The reversal of 139688761 is 167886931.

The square root of 139688761 is 11819.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 100701225 + 38987536 = 10035^2 + 6244^2 .

It is not a de Polignac number, because 139688761 - 2¹⁵ = 139655993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (139688767) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 626296 + ... + 626518.

Almost surely, 2^139688761 is an apocalyptic number.

139688761 is the 11819-th square number.

139688761 is the 5910-th centered octagonal number.

It is an amenable number.

139688761 is a deficient number, since it is larger than the sum of its proper divisors (3326678).

139688761 is an frugal number, since it uses more digits than its factorization.

139688761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 552 (or 276 counting only the distinct ones).

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

The cubic root of 139688761 is about 518.8643373848.

Multiplying 139688761 by its sum of digits (49), we get a square (6844749289 = 82733²).

It can be divided in two parts, 139 and 688761, that added together give a square (688900 = 830²).

The spelling of 139688761 in words is "one hundred thirty-nine million, six hundred eighty-eight thousand, seven hundred sixty-one".