1491551 has 4 divisors (see below), whose sum is σ = 1508400. Its totient is φ = 1474704.

The previous prime is 1491547. The next prime is 1491571. The reversal of 1491551 is 1551941.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1551941 = 509 ⋅3049.

It is a cyclic number.

It is not a de Polignac number, because 1491551 - 2² = 1491547 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1491551.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1491521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8291 + ... + 8468.

It is an arithmetic number, because the mean of its divisors is an integer number (377100).

2^1491551 is an apocalyptic number.

1491551 is a deficient number, since it is larger than the sum of its proper divisors (16849).

1491551 is an equidigital number, since it uses as much as digits as its factorization.

1491551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16848.

The product of its digits is 900, while the sum is 26.

The square root of 1491551 is about 1221.2907106828. The cubic root of 1491551 is about 114.2560929929.

The spelling of 1491551 in words is "one million, four hundred ninety-one thousand, five hundred fifty-one".