21155335442356 has 48 divisors (see below), whose sum is σ = 37696785057792. Its totient is φ = 10386614448000.

The previous prime is 21155335442347. The next prime is 21155335442363. The reversal of 21155335442356 is 65324453355112.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 140560015 + ... + 140710441.

It is an arithmetic number, because the mean of its divisors is an integer number (785349688704).

Almost surely, 2^{21155335442356} is an apocalyptic number.

It is an amenable number.

21155335442356 is a deficient number, since it is larger than the sum of its proper divisors (16541449615436).

21155335442356 is a wasteful number, since it uses less digits than its factorization.

21155335442356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 153400 (or 153398 counting only the distinct ones).

The product of its digits is 6480000, while the sum is 49.

Adding to 21155335442356 its reverse (65324453355112), we get a palindrome (86479788797468).

The spelling of 21155335442356 in words is "twenty-one trillion, one hundred fifty-five billion, three hundred thirty-five million, four hundred forty-two thousand, three hundred fifty-six".