1491731 has 4 divisors (see below), whose sum is σ = 1543200. Its totient is φ = 1440264.

The previous prime is 1491727. The next prime is 1491739. The reversal of 1491731 is 1371941.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1371941 = 823 ⋅1667.

It is a cyclic number.

It is not a de Polignac number, because 1491731 - 2² = 1491727 is a prime.

It is a super-2 number, since 2×1491731² = 4450522752722, which contains 22 as substring.

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 1491731.

It is not an unprimeable number, because it can be changed into a prime (1491739) 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, 25691 + ... + 25748.

It is an arithmetic number, because the mean of its divisors is an integer number (385800).

2^1491731 is an apocalyptic number.

1491731 is a deficient number, since it is larger than the sum of its proper divisors (51469).

1491731 is an equidigital number, since it uses as much as digits as its factorization.

1491731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 51468.

The product of its digits is 756, while the sum is 26.

The square root of 1491731 is about 1221.3644009877. The cubic root of 1491731 is about 114.2606889402.

It can be divided in two parts, 1491 and 731, that added together give a palindrome (2222).

The spelling of 1491731 in words is "one million, four hundred ninety-one thousand, seven hundred thirty-one".