21938115087 has 48 divisors (see below), whose sum is σ = 37590705152. Its totient is φ = 12524686560.

The previous prime is 21938115049. The next prime is 21938115107. The reversal of 21938115087 is 78051183912.

21938115087 is a `hidden beast` number, since 219 + 381 + 1 + 50 + 8 + 7 = 666.

It is not a de Polignac number, because 21938115087 - 2¹⁰ = 21938114063 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21938114087) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2088693 + ... + 2099169.

Almost surely, 2^21938115087 is an apocalyptic number.

21938115087 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

21938115087 is a deficient number, since it is larger than the sum of its proper divisors (15652590065).

21938115087 is a wasteful number, since it uses less digits than its factorization.

21938115087 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11730 (or 11718 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 45.

Adding to 21938115087 its reverse (78051183912), we get a palindrome (99989298999).

The spelling of 21938115087 in words is "twenty-one billion, nine hundred thirty-eight million, one hundred fifteen thousand, eighty-seven".