661241245354 has 4 divisors (see below), whose sum is σ = 991861868034. Its totient is φ = 330620622676.

The previous prime is 661241245309. The next prime is 661241245363. The reversal of 661241245354 is 453542142166.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 453542142166 = 2 ⋅226771071083.

It can be written as a sum of positive squares in only one way, i.e., 526865481025 + 134375764329 = 725855^2 + 366573^2 .

It is a super-3 number, since 3×661241245354³ (a number of 36 digits) contains 333 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 661241245354.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 165310311337 + ... + 165310311340.

Almost surely, 2^661241245354 is an apocalyptic number.

661241245354 is a deficient number, since it is larger than the sum of its proper divisors (330620622680).

661241245354 is a wasteful number, since it uses less digits than its factorization.

661241245354 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 330620622679.

The product of its digits is 691200, while the sum is 43.

The spelling of 661241245354 in words is "six hundred sixty-one billion, two hundred forty-one million, two hundred forty-five thousand, three hundred fifty-four".