61804015571809 has 9 divisors (see below), whose sum is σ = 71894531109297. Its totient is φ = 52974823320804.

The previous prime is 61804015571807. The next prime is 61804015571839. The reversal of 61804015571809 is 90817551040816.

The square root of 61804015571809 is 7861553.

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

It is not a de Polignac number, because 61804015571809 - 2¹ = 61804015571807 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 61804015571809.

It is not an unprimeable number, because it can be changed into a prime (61804015571807) 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, 54469332 + ... + 55592410.

Almost surely, 2^{61804015571809} is an apocalyptic number.

61804015571809 is the 7861553-rd square number.

61804015571809 is the 3930777-th centered octagonal number.

It is an amenable number.

61804015571809 is a deficient number, since it is larger than the sum of its proper divisors (10090515537488).

61804015571809 is an frugal number, since it uses more digits than its factorization.

61804015571809 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2246172 (or 1123086 counting only the distinct ones).

The product of its (nonzero) digits is 2419200, while the sum is 55.

The spelling of 61804015571809 in words is "sixty-one trillion, eight hundred four billion, fifteen million, five hundred seventy-one thousand, eight hundred nine".