21154147741 has 4 divisors (see below), whose sum is σ = 21182093212. Its totient is φ = 21126202272.

The previous prime is 21154147733. The next prime is 21154147769. The reversal of 21154147741 is 14774145112.

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 11874678841 + 9279468900 = 108971^2 + 96330^2 .

It is a cyclic number.

It is not a de Polignac number, because 21154147741 - 2³ = 21154147733 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21154147741.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21154147771) 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, 13971600 + ... + 13973113.

It is an arithmetic number, because the mean of its divisors is an integer number (5295523303).

Almost surely, 2^21154147741 is an apocalyptic number.

It is an amenable number.

21154147741 is a deficient number, since it is larger than the sum of its proper divisors (27945471).

21154147741 is an equidigital number, since it uses as much as digits as its factorization.

21154147741 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27945470.

The product of its digits is 31360, while the sum is 37.

The spelling of 21154147741 in words is "twenty-one billion, one hundred fifty-four million, one hundred forty-seven thousand, seven hundred forty-one".