221501201102155 has 48 divisors (see below), whose sum is σ = 302761647707904. Its totient is φ = 154625015266560.

The previous prime is 221501201102099. The next prime is 221501201102173. The reversal of 221501201102155 is 551201102105122.

It is not a de Polignac number, because 221501201102155 - 2¹⁵ = 221501201069387 is a prime.

It is a super-3 number, since 3×221501201102155³ (a number of 44 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 579142 + ... + 21055588.

It is an arithmetic number, because the mean of its divisors is an integer number (6307534327248).

Almost surely, 2^{221501201102155} is an apocalyptic number.

221501201102155 is a deficient number, since it is larger than the sum of its proper divisors (81260446605749).

221501201102155 is a wasteful number, since it uses less digits than its factorization.

221501201102155 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20476964 (or 20476945 counting only the distinct ones).

The product of its (nonzero) digits is 2000, while the sum is 28.

Adding to 221501201102155 its reverse (551201102105122), we get a palindrome (772702303207277).

The spelling of 221501201102155 in words is "two hundred twenty-one trillion, five hundred one billion, two hundred one million, one hundred two thousand, one hundred fifty-five".