76421641661 has 8 divisors (see below), whose sum is σ = 76599971640. Its totient is φ = 76243511808.

The previous prime is 76421641649. The next prime is 76421641663. The reversal of 76421641661 is 16614612467.

It can be written as a sum of positive squares in 4 ways, for example, as 780140761 + 75641500900 = 27931^2 + 275030^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 76421641661 - 2¹⁰ = 76421640637 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (76421641663) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 728645 + ... + 826901.

It is an arithmetic number, because the mean of its divisors is an integer number (9574996455).

Almost surely, 2^76421641661 is an apocalyptic number.

It is an amenable number.

76421641661 is a deficient number, since it is larger than the sum of its proper divisors (178329979).

76421641661 is a wasteful number, since it uses less digits than its factorization.

76421641661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 100063.

The product of its digits is 290304, while the sum is 44.

The spelling of 76421641661 in words is "seventy-six billion, four hundred twenty-one million, six hundred forty-one thousand, six hundred sixty-one".