21112144157 has 4 divisors (see below), whose sum is σ = 22736155260. Its totient is φ = 19488133056.

The previous prime is 21112144147. The next prime is 21112144169. The reversal of 21112144157 is 75144121112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13157466436 + 7954677721 = 114706^2 + 89189^2 .

It is a cyclic number.

It is not a de Polignac number, because 21112144157 - 2¹⁶ = 21112078621 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21112144147) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 812005532 + ... + 812005557.

It is an arithmetic number, because the mean of its divisors is an integer number (5684038815).

Almost surely, 2^21112144157 is an apocalyptic number.

It is an amenable number.

21112144157 is a deficient number, since it is larger than the sum of its proper divisors (1624011103).

21112144157 is a wasteful number, since it uses less digits than its factorization.

21112144157 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1624011102.

The product of its digits is 2240, while the sum is 29.

Adding to 21112144157 its reverse (75144121112), we get a palindrome (96256265269).

The spelling of 21112144157 in words is "twenty-one billion, one hundred twelve million, one hundred forty-four thousand, one hundred fifty-seven".