21861446741 has 4 divisors (see below), whose sum is σ = 21897462912. Its totient is φ = 21825430572.

The previous prime is 21861446723. The next prime is 21861446839. The reversal of 21861446741 is 14764416812.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21861446741 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21861446692 and 21861446701.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21861446141) 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, 18007175 + ... + 18008388.

It is an arithmetic number, because the mean of its divisors is an integer number (5474365728).

Almost surely, 2^21861446741 is an apocalyptic number.

It is an amenable number.

21861446741 is a deficient number, since it is larger than the sum of its proper divisors (36016171).

21861446741 is an equidigital number, since it uses as much as digits as its factorization.

21861446741 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 36016170.

The product of its digits is 258048, while the sum is 44.

The spelling of 21861446741 in words is "twenty-one billion, eight hundred sixty-one million, four hundred forty-six thousand, seven hundred forty-one".