999739006421 has 2 divisors, whose sum is σ = 999739006422. Its totient is φ = 999739006420.

The previous prime is 999739006403. The next prime is 999739006451. The reversal of 999739006421 is 124600937999.

999739006421 = 707014² + 707015².

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 499870210225 + 499868796196 = 707015^2 + 707014^2 .

It is a cyclic number.

It is not a de Polignac number, because 999739006421 - 2¹⁴ = 999738990037 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (999739006451) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 499869503210 + 499869503211.

It is an arithmetic number, because the mean of its divisors is an integer number (499869503211).

Almost surely, 2^999739006421 is an apocalyptic number.

999739006421 is the 707015-th centered square number.

It is an amenable number.

999739006421 is a deficient number, since it is larger than the sum of its proper divisors (1).

999739006421 is an equidigital number, since it uses as much as digits as its factorization.

999739006421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6613488, while the sum is 59.

The spelling of 999739006421 in words is "nine hundred ninety-nine billion, seven hundred thirty-nine million, six thousand, four hundred twenty-one".