55681631 has 2 divisors, whose sum is σ = 55681632. Its totient is φ = 55681630.

The previous prime is 55681583. The next prime is 55681721. The reversal of 55681631 is 13618655.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-55681631 is a prime.

It is a super-2 number, since 2×55681631² = 6200888061640322, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 55681591 and 55681600.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55681331) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27840815 + 27840816.

It is an arithmetic number, because the mean of its divisors is an integer number (27840816).

Almost surely, 2^55681631 is an apocalyptic number.

55681631 is a deficient number, since it is larger than the sum of its proper divisors (1).

55681631 is an equidigital number, since it uses as much as digits as its factorization.

55681631 is an evil number, because the sum of its binary digits is even.

The product of its digits is 21600, while the sum is 35.

The square root of 55681631 is about 7462.0125301423. The cubic root of 55681631 is about 381.8598368301.

The spelling of 55681631 in words is "fifty-five million, six hundred eighty-one thousand, six hundred thirty-one".