2021651 has 2 divisors, whose sum is σ = 2021652. Its totient is φ = 2021650.

The previous prime is 2021647. The next prime is 2021653. The reversal of 2021651 is 1561202.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2021651 - 2² = 2021647 is a prime.

Together with 2021653, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (2021653) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1010825 + 1010826.

It is an arithmetic number, because the mean of its divisors is an integer number (1010826).

2^2021651 is an apocalyptic number.

2021651 is a deficient number, since it is larger than the sum of its proper divisors (1).

2021651 is an equidigital number, since it uses as much as digits as its factorization.

2021651 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 120, while the sum is 17.

The square root of 2021651 is about 1421.8477414970. The cubic root of 2021651 is about 126.4451167189.

Adding to 2021651 its reverse (1561202), we get a palindrome (3582853).

The spelling of 2021651 in words is "two million, twenty-one thousand, six hundred fifty-one".