1390506728 has 64 divisors (see below), whose sum is σ = 2872920960. Its totient is φ = 626985216.

The previous prime is 1390506727. The next prime is 1390506751. The reversal of 1390506728 is 8276050931.

It is a super-2 number, since 2×1390506728² = 3867017921226531968, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (1390506727) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1912301 + ... + 1913027.

It is an arithmetic number, because the mean of its divisors is an integer number (44889390).

Almost surely, 2^1390506728 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1390506728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1436460480).

1390506728 is an abundant number, since it is smaller than the sum of its proper divisors (1482414232).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1390506728 is a wasteful number, since it uses less digits than its factorization.

1390506728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1146 (or 1142 counting only the distinct ones).

The product of its (nonzero) digits is 90720, while the sum is 41.

The square root of 1390506728 is about 37289.4988971426. The cubic root of 1390506728 is about 1116.1546292937.

The spelling of 1390506728 in words is "one billion, three hundred ninety million, five hundred six thousand, seven hundred twenty-eight".