1339666021 has 4 divisors (see below), whose sum is σ = 1372340844. Its totient is φ = 1306991200.

The previous prime is 1339666019. The next prime is 1339666037. The reversal of 1339666021 is 1206669331.

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 473541121 + 866124900 = 21761^2 + 29430^2 .

It is a cyclic number.

It is not a de Polignac number, because 1339666021 - 2¹ = 1339666019 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 (1339666091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16337350 + ... + 16337431.

It is an arithmetic number, because the mean of its divisors is an integer number (343085211).

Almost surely, 2^1339666021 is an apocalyptic number.

It is an amenable number.

1339666021 is a deficient number, since it is larger than the sum of its proper divisors (32674823).

1339666021 is an equidigital number, since it uses as much as digits as its factorization.

1339666021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32674822.

The product of its (nonzero) digits is 34992, while the sum is 37.

The square root of 1339666021 is about 36601.4483456598. The cubic root of 1339666021 is about 1102.3821710313.

The spelling of 1339666021 in words is "one billion, three hundred thirty-nine million, six hundred sixty-six thousand, twenty-one".