1615631 has 2 divisors, whose sum is σ = 1615632. Its totient is φ = 1615630.

The previous prime is 1615613. The next prime is 1615633. The reversal of 1615631 is 1365161.

It is a happy number.

Together with previous prime (1615613) it forms an Ormiston pair, because they use the same digits, order apart.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 1615631 - 2¹⁸ = 1353487 is a prime.

It is a super-2 number, since 2×1615631² = 5220527056322, which contains 22 as substring.

Together with 1615633, 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 = 1615597 and 1615606.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1615633) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 807815 + 807816.

It is an arithmetic number, because the mean of its divisors is an integer number (807816).

2^1615631 is an apocalyptic number.

1615631 is a deficient number, since it is larger than the sum of its proper divisors (1).

1615631 is an equidigital number, since it uses as much as digits as its factorization.

1615631 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 540, while the sum is 23.

The square root of 1615631 is about 1271.0747420982. The cubic root of 1615631 is about 117.3403535816.

The spelling of 1615631 in words is "one million, six hundred fifteen thousand, six hundred thirty-one".