2139739956225 has 81 divisors (see below), whose sum is σ = 3871213945417. Its totient is φ = 1129784920320.

The previous prime is 2139739956223. The next prime is 2139739956229. The reversal of 2139739956225 is 5226599379312.

It is a happy number.

The square root of 2139739956225 is 1462785.

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

2139739956225 is a `hidden beast` number, since 2 + 1 + 39 + 7 + 39 + 9 + 562 + 2 + 5 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 1088614696689 + 1051125259536 = 1043367^2 + 1025244^2 .

It is not a de Polignac number, because 2139739956225 - 2¹ = 2139739956223 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2139739956223) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 2479420144 + ... + 2479421006.

Almost surely, 2^{2139739956225} is an apocalyptic number.

2139739956225 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

2139739956225 is the 1462785-th square number.

2139739956225 is the 731393-rd centered octagonal number.

It is an amenable number.

2139739956225 is a deficient number, since it is larger than the sum of its proper divisors (1731473989192).

2139739956225 is an frugal number, since it uses more digits than its factorization.

2139739956225 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1968 (or 984 counting only the distinct ones).

The product of its digits is 55112400, while the sum is 63.

The spelling of 2139739956225 in words is "two trillion, one hundred thirty-nine billion, seven hundred thirty-nine million, nine hundred fifty-six thousand, two hundred twenty-five".