2139216381 has 12 divisors (see below), whose sum is σ = 3140635420. Its totient is φ = 1402764480.

The previous prime is 2139216379. The next prime is 2139216397. The reversal of 2139216381 is 1836129312.

2139216381 is a `hidden beast` number, since 2 + 13 + 9 + 2 + 1 + 638 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 1059502500 + 1079713881 = 32550^2 + 32859^2 .

It is not a de Polignac number, because 2139216381 - 2¹ = 2139216379 is a prime.

It is a super-2 number, since 2×2139216381² = 9152493449477474322, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2139216181) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1947736 + ... + 1948833.

Almost surely, 2^2139216381 is an apocalyptic number.

It is an amenable number.

2139216381 is a deficient number, since it is larger than the sum of its proper divisors (1001419039).

2139216381 is a wasteful number, since it uses less digits than its factorization.

2139216381 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3896636 (or 3896633 counting only the distinct ones).

The product of its digits is 15552, while the sum is 36.

The square root of 2139216381 is about 46251.6635484606. The cubic root of 2139216381 is about 1288.5014308976.

It can be divided in two parts, 21392 and 16381, that added together give a palindrome (37773).

The spelling of 2139216381 in words is "two billion, one hundred thirty-nine million, two hundred sixteen thousand, three hundred eighty-one".