21195061 has 2 divisors, whose sum is σ = 21195062. Its totient is φ = 21195060.

The previous prime is 21195059. The next prime is 21195077. The reversal of 21195061 is 16059112.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19412836 + 1782225 = 4406^2 + 1335^2 .

It is a cyclic number.

It is not a de Polignac number, because 21195061 - 2¹ = 21195059 is a prime.

It is a super-2 number, since 2×21195061² = 898461221587442, which contains 22 as substring.

Together with 21195059, it forms a pair of twin primes.

It is equal to p_1341493 and since 21195061 and 1341493 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21195091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10597530 + 10597531.

It is an arithmetic number, because the mean of its divisors is an integer number (10597531).

Almost surely, 2^21195061 is an apocalyptic number.

It is an amenable number.

21195061 is a deficient number, since it is larger than the sum of its proper divisors (1).

21195061 is an equidigital number, since it uses as much as digits as its factorization.

21195061 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 540, while the sum is 25.

The square root of 21195061 is about 4603.8094009201. The cubic root of 21195061 is about 276.7440062167.

The spelling of 21195061 in words is "twenty-one million, one hundred ninety-five thousand, sixty-one".