61443602928409 has 27 divisors (see below), whose sum is σ = 66736036666719. Its totient is φ = 56545130406960.

The previous prime is 61443602928397. The next prime is 61443602928427. The reversal of 61443602928409 is 90482920634416.

The square root of 61443602928409 is 7838597.

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., 9089290374025 + 52354312554384 = 3014845^2 + 7235628^2 .

It is not a de Polignac number, because 61443602928409 - 2¹¹ = 61443602926361 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61443602928469) 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, 43919658292 + ... + 43919659690.

Almost surely, 2^{61443602928409} is an apocalyptic number.

61443602928409 is the 7838597-th square number.

61443602928409 is the 3919299-th centered octagonal number.

It is an amenable number.

61443602928409 is a deficient number, since it is larger than the sum of its proper divisors (5292433738310).

61443602928409 is an frugal number, since it uses more digits than its factorization.

61443602928409 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3686 (or 1843 counting only the distinct ones).

The product of its (nonzero) digits is 17915904, while the sum is 58.

The spelling of 61443602928409 in words is "sixty-one trillion, four hundred forty-three billion, six hundred two million, nine hundred twenty-eight thousand, four hundred nine".