74347921661 has 8 divisors (see below), whose sum is σ = 80070606840. Its totient is φ = 68625752832.

The previous prime is 74347921603. The next prime is 74347921733. The reversal of 74347921661 is 16612974347.

74347921661 = 192805² + 192806².

It can be written as a sum of positive squares in 4 ways, for example, as 31048554436 + 43299367225 = 176206^2 + 208085^2 .

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

It is not a de Polignac number, because 74347921661 - 2¹⁸ = 74347659517 is a prime.

It is a super-2 number, since 2×74347921661² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (74347921561) 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, 201305 + ... + 434993.

It is an arithmetic number, because the mean of its divisors is an integer number (10008825855).

Almost surely, 2^74347921661 is an apocalyptic number.

74347921661 is the 192806-th centered square number.

It is an amenable number.

74347921661 is a deficient number, since it is larger than the sum of its proper divisors (5722685179).

74347921661 is a wasteful number, since it uses less digits than its factorization.

74347921661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 258175.

The product of its digits is 1524096, while the sum is 50.

The spelling of 74347921661 in words is "seventy-four billion, three hundred forty-seven million, nine hundred twenty-one thousand, six hundred sixty-one".