21315355641 has 24 divisors (see below), whose sum is σ = 31667613120. Its totient is φ = 13805786016.

The previous prime is 21315355609. The next prime is 21315355687. The reversal of 21315355641 is 14655351312.

21315355641 is a `hidden beast` number, since 2 + 1 + 3 + 1 + 5 + 3 + 5 + 5 + 641 = 666.

It is not a de Polignac number, because 21315355641 - 2⁵ = 21315355609 is a prime.

It is a super-2 number, since 2×21315355641² (a number of 21 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21315355596 and 21315355605.

It is not an unprimeable number, because it can be changed into a prime (21315355741) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 180580 + ... + 274298.

It is an arithmetic number, because the mean of its divisors is an integer number (1319483880).

Almost surely, 2^21315355641 is an apocalyptic number.

It is an amenable number.

21315355641 is a deficient number, since it is larger than the sum of its proper divisors (10352257479).

21315355641 is a wasteful number, since it uses less digits than its factorization.

21315355641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94445 (or 94442 counting only the distinct ones).

The product of its digits is 54000, while the sum is 36.

The spelling of 21315355641 in words is "twenty-one billion, three hundred fifteen million, three hundred fifty-five thousand, six hundred forty-one".