61866420601441 has 9 divisors (see below), whose sum is σ = 61912239700689. Its totient is φ = 61820635403700.

The previous prime is 61866420601411. The next prime is 61866420601499. The reversal of 61866420601441 is 14410602466816.

It is a happy number.

The square root of 61866420601441 is 7865521.

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

It is not a de Polignac number, because 61866420601441 - 2²⁵ = 61866387047009 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (61866420601411) 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, 16761423406 + ... + 16761427096.

It is an arithmetic number, because the mean of its divisors is an integer number (6879137744521).

Almost surely, 2^{61866420601441} is an apocalyptic number.

61866420601441 is the 7865521-st square number and also the 4541161-st octagonal number.

61866420601441 is the 3932761-st centered octagonal number.

It is an amenable number.

61866420601441 is a deficient number, since it is larger than the sum of its proper divisors (45819099248).

61866420601441 is an frugal number, since it uses more digits than its factorization.

61866420601441 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11644 (or 5822 counting only the distinct ones).

The product of its (nonzero) digits is 1327104, while the sum is 49.

The spelling of 61866420601441 in words is "sixty-one trillion, eight hundred sixty-six billion, four hundred twenty million, six hundred one thousand, four hundred forty-one".