1399619021 has 6 divisors (see below), whose sum is σ = 1477160622. Its totient is φ = 1325954520.

The previous prime is 1399618991. The next prime is 1399619029. The reversal of 1399619021 is 1209169931.

It can be written as a sum of positive squares in only one way, i.e., 1399582921 + 36100 = 37411^2 + 190^2 .

It is not a de Polignac number, because 1399619021 - 2¹⁴ = 1399602637 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1399619021.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1399619029) 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 5 ways as a sum of consecutive naturals, for example, 1938170 + ... + 1938891.

It is an arithmetic number, because the mean of its divisors is an integer number (246193437).

Almost surely, 2^1399619021 is an apocalyptic number.

It is an amenable number.

1399619021 is a deficient number, since it is larger than the sum of its proper divisors (77541601).

1399619021 is an equidigital number, since it uses as much as digits as its factorization.

1399619021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3877099 (or 3877080 counting only the distinct ones).

The product of its (nonzero) digits is 26244, while the sum is 41.

The square root of 1399619021 is about 37411.4824753043. The cubic root of 1399619021 is about 1118.5874574004.

The spelling of 1399619021 in words is "one billion, three hundred ninety-nine million, six hundred nineteen thousand, twenty-one".