2155503444321 has 32 divisors (see below), whose sum is σ = 2931679941120. Its totient is φ = 1408459101696.

The previous prime is 2155503444307. The next prime is 2155503444337. The reversal of 2155503444321 is 1234443055512.

It is not a de Polignac number, because 2155503444321 - 2¹⁵ = 2155503411553 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2155503444321.

It is not an unprimeable number, because it can be changed into a prime (2155503444371) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 122888970 + ... + 122906508.

It is an arithmetic number, because the mean of its divisors is an integer number (91614998160).

Almost surely, 2^{2155503444321} is an apocalyptic number.

It is an amenable number.

2155503444321 is a deficient number, since it is larger than the sum of its proper divisors (776176496799).

2155503444321 is a wasteful number, since it uses less digits than its factorization.

2155503444321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21693.

The product of its (nonzero) digits is 288000, while the sum is 39.

Adding to 2155503444321 its reverse (1234443055512), we get a palindrome (3389946499833).

The spelling of 2155503444321 in words is "two trillion, one hundred fifty-five billion, five hundred three million, four hundred forty-four thousand, three hundred twenty-one".