861554101 has 4 divisors (see below), whose sum is σ = 912233772. Its totient is φ = 810874432.

The previous prime is 861554093. The next prime is 861554117. The reversal of 861554101 is 101455168.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 677300625 + 184253476 = 26025^2 + 13574^2 .

It is not a de Polignac number, because 861554101 - 2³ = 861554093 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (861554501) 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, 25339810 + ... + 25339843.

It is an arithmetic number, because the mean of its divisors is an integer number (228058443).

Almost surely, 2^861554101 is an apocalyptic number.

It is an amenable number.

861554101 is a deficient number, since it is larger than the sum of its proper divisors (50679671).

861554101 is a wasteful number, since it uses less digits than its factorization.

861554101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50679670.

The product of its (nonzero) digits is 4800, while the sum is 31.

The square root of 861554101 is about 29352.2418394234. The cubic root of 861554101 is about 951.5410265066.

The spelling of 861554101 in words is "eight hundred sixty-one million, five hundred fifty-four thousand, one hundred one".