69405561 has 9 divisors (see below), whose sum is σ = 100288591. Its totient is φ = 46253712.

The previous prime is 69405551. The next prime is 69405587. The reversal of 69405561 is 16550496.

The square root of 69405561 is 8331.

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

69405561 is a `hidden beast` number, since 6 + 94 + 0 + 5 + 561 = 666.

It can be written as a sum of positive squares in only one way, i.e., 10791225 + 58614336 = 3285^2 + 7656^2 .

It is a tau number, because it is divible by the number of its divisors (9).

It is not a de Polignac number, because 69405561 - 2¹³ = 69397369 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (69405551) 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, 23605 + ... + 26381.

Almost surely, 2^69405561 is an apocalyptic number.

69405561 is the 8331-st square number.

69405561 is the 4166-th centered octagonal number.

It is an amenable number.

69405561 is a deficient number, since it is larger than the sum of its proper divisors (30883030).

69405561 is an frugal number, since it uses more digits than its factorization.

69405561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5560 (or 2780 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 36.

The cubic root of 69405561 is about 410.9586155429.

Multiplying 69405561 by its sum of digits (36), we get a square (2498600196 = 49986²).

Multiplying 69405561 by its product of nonzero digits (32400), we get a square (2248740176400 = 1499580²).

The spelling of 69405561 in words is "sixty-nine million, four hundred five thousand, five hundred sixty-one".