28951631 has 2 divisors, whose sum is σ = 28951632. Its totient is φ = 28951630.

The previous prime is 28951627. The next prime is 28951633. The reversal of 28951631 is 13615982.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 28951631 - 2² = 28951627 is a prime.

It is a super-2 number, since 2×28951631² = 1676393875120322, which contains 22 as substring.

Together with 28951633, 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 = 28951591 and 28951600.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28951633) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14475815 + 14475816.

It is an arithmetic number, because the mean of its divisors is an integer number (14475816).

Almost surely, 2^28951631 is an apocalyptic number.

28951631 is a deficient number, since it is larger than the sum of its proper divisors (1).

28951631 is an equidigital number, since it uses as much as digits as its factorization.

28951631 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12960, while the sum is 35.

The square root of 28951631 is about 5380.6719840555. The cubic root of 28951631 is about 307.0607772946.

The spelling of 28951631 in words is "twenty-eight million, nine hundred fifty-one thousand, six hundred thirty-one".