661010046401 has 4 divisors (see below), whose sum is σ = 661083492804. Its totient is φ = 660936600000.

The previous prime is 661010046371. The next prime is 661010046421. The reversal of 661010046401 is 104640010166.

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 172407648400 + 488602398001 = 415220^2 + 699001^2 .

It is a cyclic number.

It is not a de Polignac number, because 661010046401 - 2¹⁴ = 661010030017 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (661010046421) 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, 36709700 + ... + 36727701.

It is an arithmetic number, because the mean of its divisors is an integer number (165270873201).

Almost surely, 2^661010046401 is an apocalyptic number.

It is an amenable number.

661010046401 is a deficient number, since it is larger than the sum of its proper divisors (73446403).

661010046401 is an equidigital number, since it uses as much as digits as its factorization.

661010046401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 73446402.

The product of its (nonzero) digits is 3456, while the sum is 29.

Adding to 661010046401 its reverse (104640010166), we get a palindrome (765650056567).

The spelling of 661010046401 in words is "six hundred sixty-one billion, ten million, forty-six thousand, four hundred one".