21438149375 has 10 divisors (see below), whose sum is σ = 26789112240. Its totient is φ = 17150519000.

The previous prime is 21438149371. The next prime is 21438149389. The reversal of 21438149375 is 57394183412.

It is not a de Polignac number, because 21438149375 - 2² = 21438149371 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21438149371) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 17149895 + ... + 17151144.

It is an arithmetic number, because the mean of its divisors is an integer number (2678911224).

Almost surely, 2^21438149375 is an apocalyptic number.

21438149375 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21438149375 is a deficient number, since it is larger than the sum of its proper divisors (5350962865).

21438149375 is an frugal number, since it uses more digits than its factorization.

21438149375 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34301059 (or 34301044 counting only the distinct ones).

The product of its digits is 725760, while the sum is 47.

It can be divided in two parts, 2143 and 8149375, that added together give a palindrome (8151518).

The spelling of 21438149375 in words is "twenty-one billion, four hundred thirty-eight million, one hundred forty-nine thousand, three hundred seventy-five".