161212015555 has 4 divisors (see below), whose sum is σ = 193454418672. Its totient is φ = 128969612440.

The previous prime is 161212015543. The next prime is 161212015561. The reversal of 161212015555 is 555510212161.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 555510212161 = 36761 ⋅15111401.

It is not a de Polignac number, because 161212015555 - 2²¹ = 161209918403 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 161212015555.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16121201551 + ... + 16121201560.

It is an arithmetic number, because the mean of its divisors is an integer number (48363604668).

Almost surely, 2^161212015555 is an apocalyptic number.

161212015555 is a deficient number, since it is larger than the sum of its proper divisors (32242403117).

161212015555 is an equidigital number, since it uses as much as digits as its factorization.

161212015555 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32242403116.

The product of its (nonzero) digits is 15000, while the sum is 34.

The spelling of 161212015555 in words is "one hundred sixty-one billion, two hundred twelve million, fifteen thousand, five hundred fifty-five".