1388890 has 8 divisors (see below), whose sum is σ = 2500020. Its totient is φ = 555552.

The previous prime is 1388887. The next prime is 1388927. The reversal of 1388890 is 988831.

It can be written as a sum of positive squares in 2 ways, for example, as 1125721 + 263169 = 1061^2 + 513^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 69435 + ... + 69454.

2^1388890 is an apocalyptic number.

1388890 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1388890 is a deficient number, since it is larger than the sum of its proper divisors (1111130).

1388890 is a wasteful number, since it uses less digits than its factorization.

1388890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 138896.

The product of its (nonzero) digits is 13824, while the sum is 37.

The square root of 1388890 is about 1178.5117733820. The cubic root of 1388890 is about 111.5721880996.

It can be divided in two parts, 1388 and 890, that added together give a triangular number (2278 = T₆₇).

The spelling of 1388890 in words is "one million, three hundred eighty-eight thousand, eight hundred ninety".