21625061 has 2 divisors, whose sum is σ = 21625062. Its totient is φ = 21625060.

The previous prime is 21625033. The next prime is 21625063. The reversal of 21625061 is 16052612.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12292036 + 9333025 = 3506^2 + 3055^2 .

It is a cyclic number.

It is not a de Polignac number, because 21625061 - 2¹⁸ = 21362917 is a prime.

Together with 21625063, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21625063) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10812530 + 10812531.

It is an arithmetic number, because the mean of its divisors is an integer number (10812531).

Almost surely, 2^21625061 is an apocalyptic number.

It is an amenable number.

21625061 is a deficient number, since it is larger than the sum of its proper divisors (1).

21625061 is an equidigital number, since it uses as much as digits as its factorization.

21625061 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 21625061 is about 4650.2753681906. The cubic root of 21625061 is about 278.6029947386.

Adding to 21625061 its reverse (16052612), we get a palindrome (37677673).

The spelling of 21625061 in words is "twenty-one million, six hundred twenty-five thousand, sixty-one".