23778991 has 2 divisors, whose sum is σ = 23778992. Its totient is φ = 23778990.

The previous prime is 23778983. The next prime is 23779003. The reversal of 23778991 is 19987732.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 23778991 - 2³ = 23778983 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (23778091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11889495 + 11889496.

It is an arithmetic number, because the mean of its divisors is an integer number (11889496).

Almost surely, 2^23778991 is an apocalyptic number.

23778991 is a deficient number, since it is larger than the sum of its proper divisors (1).

23778991 is an equidigital number, since it uses as much as digits as its factorization.

23778991 is an evil number, because the sum of its binary digits is even.

The product of its digits is 190512, while the sum is 46.

The square root of 23778991 is about 4876.3706791014. The cubic root of 23778991 is about 287.5617651796.

The spelling of 23778991 in words is "twenty-three million, seven hundred seventy-eight thousand, nine hundred ninety-one".