1551731 has 2 divisors, whose sum is σ = 1551732. Its totient is φ = 1551730.

The previous prime is 1551707. The next prime is 1551733. The reversal of 1551731 is 1371551.

It is a strong prime.

It is an emirp because it is prime and its reverse (1371551) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1551731 is a prime.

It is a super-2 number, since 2×1551731² = 4815738192722, which contains 22 as substring.

Together with 1551733, it forms a pair of twin primes.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 1551697 and 1551706.

It is not a weakly prime, because it can be changed into another prime (1551733) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 775865 + 775866.

It is an arithmetic number, because the mean of its divisors is an integer number (775866).

2^1551731 is an apocalyptic number.

1551731 is a deficient number, since it is larger than the sum of its proper divisors (1).

1551731 is an equidigital number, since it uses as much as digits as its factorization.

1551731 is an evil number, because the sum of its binary digits is even.

The product of its digits is 525, while the sum is 23.

The square root of 1551731 is about 1245.6849521448. The cubic root of 1551731 is about 115.7725179210.

The spelling of 1551731 in words is "one million, five hundred fifty-one thousand, seven hundred thirty-one".