1378990 has 16 divisors (see below), whose sum is σ = 2549952. Its totient is φ = 536544.

The previous prime is 1378969. The next prime is 1378997. The reversal of 1378990 is 998731.

It is a super-2 number, since 2×1378990² = 3803226840200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1378997) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1494 + ... + 2233.

It is an arithmetic number, because the mean of its divisors is an integer number (159372).

2^1378990 is an apocalyptic number.

1378990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1378990 is a deficient number, since it is larger than the sum of its proper divisors (1170962).

1378990 is a wasteful number, since it uses less digits than its factorization.

1378990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3771.

The product of its (nonzero) digits is 13608, while the sum is 37.

The square root of 1378990 is about 1174.3040492138. The cubic root of 1378990 is about 111.3064604206.

It can be divided in two parts, 13 and 78990, that added together give a triangular number (79003 = T₃₉₇).

The spelling of 1378990 in words is "one million, three hundred seventy-eight thousand, nine hundred ninety".