1851779361601 has 9 divisors (see below), whose sum is σ = 2005200358281. Its totient is φ = 1709318465712.

The previous prime is 1851779361587. The next prime is 1851779361617. The reversal of 1851779361601 is 1061639771581.

The square root of 1851779361601 is 1360801.

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 6528801601 + 1845250560000 = 80801^2 + 1358400^2 .

It is not a de Polignac number, because 1851779361601 - 2¹⁷ = 1851779230529 is a prime.

It is a super-2 number, since 2×1851779361601² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1851779361661) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 17638075 + ... + 17742751.

It is an arithmetic number, because the mean of its divisors is an integer number (222800039809).

Almost surely, 2^{1851779361601} is an apocalyptic number.

1851779361601 is the 1360801-st square number.

1851779361601 is the 680401-st centered octagonal number.

It is an amenable number.

1851779361601 is a deficient number, since it is larger than the sum of its proper divisors (153420996680).

1851779361601 is an frugal number, since it uses more digits than its factorization.

1851779361601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 209380 (or 104690 counting only the distinct ones).

The product of its (nonzero) digits is 1905120, while the sum is 55.

The spelling of 1851779361601 in words is "one trillion, eight hundred fifty-one billion, seven hundred seventy-nine million, three hundred sixty-one thousand, six hundred one".