23151421 has 2 divisors, whose sum is σ = 23151422. Its totient is φ = 23151420.

The previous prime is 23151419. The next prime is 23151431. The reversal of 23151421 is 12415132.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 18576100 + 4575321 = 4310^2 + 2139^2 .

It is a cyclic number.

It is not a de Polignac number, because 23151421 - 2¹ = 23151419 is a prime.

Together with 23151419, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (23151431) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 11575710 + 11575711.

It is an arithmetic number, because the mean of its divisors is an integer number (11575711).

Almost surely, 2^23151421 is an apocalyptic number.

It is an amenable number.

23151421 is a deficient number, since it is larger than the sum of its proper divisors (1).

23151421 is an equidigital number, since it uses as much as digits as its factorization.

23151421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 240, while the sum is 19.

The square root of 23151421 is about 4811.5923559670. The cubic root of 23151421 is about 285.0094220749.

Adding to 23151421 its reverse (12415132), we get a palindrome (35566553).

The spelling of 23151421 in words is "twenty-three million, one hundred fifty-one thousand, four hundred twenty-one".