61445 has 4 divisors (see below), whose sum is σ = 73740. Its totient is φ = 49152.

The previous prime is 61441. The next prime is 61463. The reversal of 61445 is 54416.

It is a happy number.

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 36481 + 24964 = 191^2 + 158^2 .

It is a cyclic number.

It is not a de Polignac number, because 61445 - 2² = 61441 is a prime.

It is a Curzon number.

It is a zygodrome in base 4.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (61441) 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, 6140 + ... + 6149.

It is an arithmetic number, because the mean of its divisors is an integer number (18435).

2⁶¹⁴⁴⁵ is an apocalyptic number.

It is an amenable number.

61445 is a deficient number, since it is larger than the sum of its proper divisors (12295).

61445 is a wasteful number, since it uses less digits than its factorization.

61445 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12294.

The product of its digits is 480, while the sum is 20.

The square root of 61445 is about 247.8810198462. The cubic root of 61445 is about 39.4604635648.

Subtracting from 61445 its sum of digits (20), we obtain a triangular number (61425 = T₃₅₀).

The spelling of 61445 in words is "sixty-one thousand, four hundred forty-five".