23137781 has 2 divisors, whose sum is σ = 23137782. Its totient is φ = 23137780.

The previous prime is 23137769. The next prime is 23137819. The reversal of 23137781 is 18773132.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 23136100 + 1681 = 4810^2 + 41^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-23137781 is a prime.

It is a super-2 number, since 2×23137781² = 1070713819207922, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (23137711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11568890 + 11568891.

It is an arithmetic number, because the mean of its divisors is an integer number (11568891).

Almost surely, 2^23137781 is an apocalyptic number.

It is an amenable number.

23137781 is a deficient number, since it is larger than the sum of its proper divisors (1).

23137781 is an equidigital number, since it uses as much as digits as its factorization.

23137781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7056, while the sum is 32.

The square root of 23137781 is about 4810.1747369508. The cubic root of 23137781 is about 284.9534385821.

The spelling of 23137781 in words is "twenty-three million, one hundred thirty-seven thousand, seven hundred eighty-one".