21770423 has 2 divisors, whose sum is σ = 21770424. Its totient is φ = 21770422.

The previous prime is 21770417. The next prime is 21770429. The reversal of 21770423 is 32407712.

It is a balanced prime because it is at equal distance from previous prime (21770417) and next prime (21770429).

It is a cyclic number.

It is not a de Polignac number, because 21770423 - 2⁴ = 21770407 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21770392 and 21770401.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21770429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10885211 + 10885212.

It is an arithmetic number, because the mean of its divisors is an integer number (10885212).

Almost surely, 2^21770423 is an apocalyptic number.

21770423 is a deficient number, since it is larger than the sum of its proper divisors (1).

21770423 is an equidigital number, since it uses as much as digits as its factorization.

21770423 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2352, while the sum is 26.

The square root of 21770423 is about 4665.8785882189. The cubic root of 21770423 is about 279.2258505346.

The spelling of 21770423 in words is "twenty-one million, seven hundred seventy thousand, four hundred twenty-three".