1521731 has 2 divisors, whose sum is σ = 1521732. Its totient is φ = 1521730.

The previous prime is 1521677. The next prime is 1521739. The reversal of 1521731 is 1371251.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1521731 - 2¹⁰ = 1520707 is a prime.

It is a super-2 number, since 2×1521731² = 4631330472722, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (1521739) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 760865 + 760866.

It is an arithmetic number, because the mean of its divisors is an integer number (760866).

2^1521731 is an apocalyptic number.

1521731 is a deficient number, since it is larger than the sum of its proper divisors (1).

1521731 is an equidigital number, since it uses as much as digits as its factorization.

1521731 is an evil number, because the sum of its binary digits is even.

The product of its digits is 210, while the sum is 20.

The square root of 1521731 is about 1233.5846140415. The cubic root of 1521731 is about 115.0215712528.

Adding to 1521731 its reverse (1371251), we get a palindrome (2892982).

The spelling of 1521731 in words is "one million, five hundred twenty-one thousand, seven hundred thirty-one".