21155360506444 has 24 divisors (see below), whose sum is σ = 37145531017728. Its totient is φ = 10542401583120.

The previous prime is 21155360506429. The next prime is 21155360506459. The reversal of 21155360506444 is 44460506355112.

It is an interprime number because it is at equal distance from previous prime (21155360506429) and next prime (21155360506459).

It is a super-2 number, since 2×21155360506444² (a number of 27 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21155360506394 and 21155360506403.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4546962 + ... + 7936345.

It is an arithmetic number, because the mean of its divisors is an integer number (1547730459072).

Almost surely, 2^{21155360506444} is an apocalyptic number.

It is an amenable number.

21155360506444 is a deficient number, since it is larger than the sum of its proper divisors (15990170511284).

21155360506444 is a wasteful number, since it uses less digits than its factorization.

21155360506444 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12484725 (or 12484723 counting only the distinct ones).

The product of its (nonzero) digits is 1728000, while the sum is 46.

The spelling of 21155360506444 in words is "twenty-one trillion, one hundred fifty-five billion, three hundred sixty million, five hundred six thousand, four hundred forty-four".