71801100443809 has 27 divisors (see below), whose sum is σ = 79892801074387. Its totient is φ = 64480348908800.

The previous prime is 71801100443797. The next prime is 71801100443827. The reversal of 71801100443809 is 90834400110817.

It is a happy number.

The square root of 71801100443809 is 8473553.

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

It can be written as a sum of positive squares in only one way, i.e., 64097589173409 + 7703511270400 = 8006097^2 + 2775520^2 .

It is not a de Polignac number, because 71801100443809 - 2²³ = 71801092055201 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71801100453809) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 7736349249 + ... + 7736358529.

Almost surely, 2^{71801100443809} is an apocalyptic number.

71801100443809 is the 8473553-rd square number.

71801100443809 is the 4236777-th centered octagonal number.

It is an amenable number.

71801100443809 is a deficient number, since it is larger than the sum of its proper divisors (8091700630578).

71801100443809 is an frugal number, since it uses more digits than its factorization.

71801100443809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18750 (or 9375 counting only the distinct ones).

The product of its (nonzero) digits is 193536, while the sum is 46.

The spelling of 71801100443809 in words is "seventy-one trillion, eight hundred one billion, one hundred million, four hundred forty-three thousand, eight hundred nine".