74651821 has 8 divisors (see below), whose sum is σ = 75488504. Its totient is φ = 73820160.

The previous prime is 74651809. The next prime is 74651849. The reversal of 74651821 is 12815647.

It can be written as a sum of positive squares in 4 ways, for example, as 9672100 + 64979721 = 3110^2 + 8061^2 .

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 74651821 - 2⁹ = 74651309 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 (74651851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 33865 + ... + 36001.

It is an arithmetic number, because the mean of its divisors is an integer number (9436063).

Almost surely, 2^74651821 is an apocalyptic number.

It is an amenable number.

74651821 is a deficient number, since it is larger than the sum of its proper divisors (836683).

74651821 is a wasteful number, since it uses less digits than its factorization.

74651821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2511.

The product of its digits is 13440, while the sum is 34.

The square root of 74651821 is about 8640.1285291366. The cubic root of 74651821 is about 421.0627300865.

The spelling of 74651821 in words is "seventy-four million, six hundred fifty-one thousand, eight hundred twenty-one".