1219389728 has 18 divisors (see below), whose sum is σ = 2401062489. Its totient is φ = 609596096.

The previous prime is 1219389683. The next prime is 1219389739. The reversal of 1219389728 is 8279839121.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in 2 ways, for example, as 718883344 + 500506384 = 26812^2 + 22372^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=24692.

It is a super-2 number, since 2×1219389728² = 2973822617503827968, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 194450 + ... + 200622.

Almost surely, 2^1219389728 is an apocalyptic number.

It is an amenable number.

1219389728 is a deficient number, since it is larger than the sum of its proper divisors (1181672761).

1219389728 is an frugal number, since it uses more digits than its factorization.

1219389728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12356 (or 6175 counting only the distinct ones).

The product of its digits is 435456, while the sum is 50.

The square root of 1219389728 is about 34919.7612821165. The cubic root of 1219389728 is about 1068.3515327345.

Multiplying 1219389728 by its sum of digits (50), we get a square (60969486400 = 246920²).

The spelling of 1219389728 in words is "one billion, two hundred nineteen million, three hundred eighty-nine thousand, seven hundred twenty-eight".