8100021 has 16 divisors (see below), whose sum is σ = 11225088. Its totient is φ = 5190000.

The previous prime is 8099999. The next prime is 8100073. The reversal of 8100021 is 1200018.

8100021 = T₁₁₈ + T₁₁₉ + ... + T₃₆₈.

It is a happy number.

It is not a de Polignac number, because 8100021 - 2¹³ = 8091829 is a prime.

It is a super-2 number, since 2×8100021² = 131220680400882, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8100091) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 23170 + ... + 23516.

It is an arithmetic number, because the mean of its divisors is an integer number (701568).

Almost surely, 2^8100021 is an apocalyptic number.

It is an amenable number.

8100021 is a deficient number, since it is larger than the sum of its proper divisors (3125067).

8100021 is a wasteful number, since it uses less digits than its factorization.

8100021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 632.

The product of its (nonzero) digits is 16, while the sum is 12.

The square root of 8100021 is about 2846.0535834731. The cubic root of 8100021 is about 200.8300585812.

Adding to 8100021 its reverse (1200018), we get a palindrome (9300039).

The spelling of 8100021 in words is "eight million, one hundred thousand, twenty-one".