10021561 has 8 divisors (see below), whose sum is σ = 11228544. Its totient is φ = 8863920.

The previous prime is 10021549. The next prime is 10021567. The reversal of 10021561 is 16512001.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 10021561 - 2⁹ = 10021049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (10021567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11905 + ... + 12718.

It is an arithmetic number, because the mean of its divisors is an integer number (1403568).

Almost surely, 2^10021561 is an apocalyptic number.

10021561 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

10021561 is a deficient number, since it is larger than the sum of its proper divisors (1206983).

10021561 is a wasteful number, since it uses less digits than its factorization.

10021561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24671.

The product of its (nonzero) digits is 60, while the sum is 16.

The square root of 10021561 is about 3165.6849179917. The cubic root of 10021561 is about 215.5981970745.

Adding to 10021561 its reverse (16512001), we get a palindrome (26533562).

The spelling of 10021561 in words is "ten million, twenty-one thousand, five hundred sixty-one".