1491988 has 24 divisors (see below), whose sum is σ = 2844072. Its totient is φ = 681984.

The previous prime is 1491979. The next prime is 1491989. The reversal of 1491988 is 8891941.

It can be written as a sum of positive squares in 4 ways, for example, as 806404 + 685584 = 898^2 + 828^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1491988.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1491989) 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, 2220 + ... + 2812.

It is an arithmetic number, because the mean of its divisors is an integer number (118503).

2^1491988 is an apocalyptic number.

It is an amenable number.

1491988 is a deficient number, since it is larger than the sum of its proper divisors (1352084).

1491988 is a wasteful number, since it uses less digits than its factorization.

1491988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 651 (or 649 counting only the distinct ones).

The product of its digits is 20736, while the sum is 40.

The square root of 1491988 is about 1221.4696066624. The cubic root of 1491988 is about 114.2672502909.

The spelling of 1491988 in words is "one million, four hundred ninety-one thousand, nine hundred eighty-eight".