72155217162170 has 8 divisors (see below), whose sum is σ = 129879390891924. Its totient is φ = 28862086864864.

The previous prime is 72155217162109. The next prime is 72155217162173. The reversal of 72155217162170 is 7126171255127.

It can be written as a sum of positive squares in 2 ways, for example, as 70463248389121 + 1691968773049 = 8394239^2 + 1300757^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (72155217162173) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3607760858099 + ... + 3607760858118.

Almost surely, 2^{72155217162170} is an apocalyptic number.

72155217162170 is a deficient number, since it is larger than the sum of its proper divisors (57724173729754).

72155217162170 is a wasteful number, since it uses less digits than its factorization.

72155217162170 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7215521716224.

The product of its (nonzero) digits is 411600, while the sum is 47.

The spelling of 72155217162170 in words is "seventy-two trillion, one hundred fifty-five billion, two hundred seventeen million, one hundred sixty-two thousand, one hundred seventy".