1398624421 has 4 divisors (see below), whose sum is σ = 1399912192. Its totient is φ = 1397336652.

The previous prime is 1398624419. The next prime is 1398624433. The reversal of 1398624421 is 1244268931.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1398624421 - 2¹ = 1398624419 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 (1398624401) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 642255 + ... + 644428.

It is an arithmetic number, because the mean of its divisors is an integer number (349978048).

Almost surely, 2^1398624421 is an apocalyptic number.

It is an amenable number.

1398624421 is a deficient number, since it is larger than the sum of its proper divisors (1287771).

1398624421 is a wasteful number, since it uses less digits than its factorization.

1398624421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1287770.

The product of its digits is 82944, while the sum is 40.

The square root of 1398624421 is about 37398.1874026001. The cubic root of 1398624421 is about 1118.3224303451.

The spelling of 1398624421 in words is "one billion, three hundred ninety-eight million, six hundred twenty-four thousand, four hundred twenty-one".