1855551101 has 2 divisors, whose sum is σ = 1855551102. Its totient is φ = 1855551100.

The previous prime is 1855551079. The next prime is 1855551119. The reversal of 1855551101 is 1011555581.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1742979001 + 112572100 = 41749^2 + 10610^2 .

It is an emirp because it is prime and its reverse (1011555581) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1855551101 - 2²⁶ = 1788442237 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1755551101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 927775550 + 927775551.

It is an arithmetic number, because the mean of its divisors is an integer number (927775551).

Almost surely, 2^1855551101 is an apocalyptic number.

It is an amenable number.

1855551101 is a deficient number, since it is larger than the sum of its proper divisors (1).

1855551101 is an equidigital number, since it uses as much as digits as its factorization.

1855551101 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5000, while the sum is 32.

The square root of 1855551101 is about 43076.1082387906. The cubic root of 1855551101 is about 1228.8276447028.

The spelling of 1855551101 in words is "one billion, eight hundred fifty-five million, five hundred fifty-one thousand, one hundred one".