1491990 has 32 divisors (see below), whose sum is σ = 3671136. Its totient is φ = 387840.

The previous prime is 1491989. The next prime is 1491991. The reversal of 1491990 is 991941.

It is an interprime number because it is at equal distance from previous prime (1491989) and next prime (1491991).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1491991) 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, 624 + ... + 1836.

It is an arithmetic number, because the mean of its divisors is an integer number (114723).

2^1491990 is an apocalyptic number.

1491990 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1491990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1835568).

1491990 is an abundant number, since it is smaller than the sum of its proper divisors (2179146).

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

1491990 is a wasteful number, since it uses less digits than its factorization.

1491990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1264.

The product of its (nonzero) digits is 2916, while the sum is 33.

The square root of 1491990 is about 1221.4704253481. The cubic root of 1491990 is about 114.2673013491.

The spelling of 1491990 in words is "one million, four hundred ninety-one thousand, nine hundred ninety".