164388891601 has 81 divisors (see below), whose sum is σ = 198200306577. Its totient is φ = 136230864000.

The previous prime is 164388891593. The next prime is 164388891607. The reversal of 164388891601 is 106198883461.

The square root of 164388891601 is 405449.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 43410139201 + 120978752400 = 208351^2 + 347820^2 .

It is not a de Polignac number, because 164388891601 - 2³ = 164388891593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (164388891607) by changing a digit.

It is a polite number, since it can be written in 80 ways as a sum of consecutive naturals, for example, 4009485141 + ... + 4009485181.

Almost surely, 2^164388891601 is an apocalyptic number.

164388891601 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

164388891601 is the 405449-th square number.

164388891601 is the 202725-th centered octagonal number.

It is an amenable number.

164388891601 is a deficient number, since it is larger than the sum of its proper divisors (33811414976).

164388891601 is an equidigital number, since it uses as much as digits as its factorization.

164388891601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 224 (or 112 counting only the distinct ones).

The product of its (nonzero) digits is 1990656, while the sum is 55.

The spelling of 164388891601 in words is "one hundred sixty-four billion, three hundred eighty-eight million, eight hundred ninety-one thousand, six hundred one".