1398221786 has 16 divisors (see below), whose sum is σ = 2319712584. Its totient is φ = 627891264.

The previous prime is 1398221731. The next prime is 1398221791. The reversal of 1398221786 is 6871228931.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 1395396025 + 2825761 = 37355^2 + 1681^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1398221786.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 725765 + ... + 727688.

Almost surely, 2^1398221786 is an apocalyptic number.

1398221786 is a deficient number, since it is larger than the sum of its proper divisors (921490798).

1398221786 is a wasteful number, since it uses less digits than its factorization.

1398221786 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1453505.

The product of its digits is 290304, while the sum is 47.

The square root of 1398221786 is about 37392.8039333773. The cubic root of 1398221786 is about 1118.2151060913.

The spelling of 1398221786 in words is "one billion, three hundred ninety-eight million, two hundred twenty-one thousand, seven hundred eighty-six".