20821607 has 2 divisors, whose sum is σ = 20821608. Its totient is φ = 20821606.

The previous prime is 20821547. The next prime is 20821609. The reversal of 20821607 is 70612802.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20821607 - 2⁸ = 20821351 is a prime.

Together with 20821609, 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 (20821609) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10410803 + 10410804.

It is an arithmetic number, because the mean of its divisors is an integer number (10410804).

Almost surely, 2^20821607 is an apocalyptic number.

20821607 is a deficient number, since it is larger than the sum of its proper divisors (1).

20821607 is an equidigital number, since it uses as much as digits as its factorization.

20821607 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 1344, while the sum is 26.

The square root of 20821607 is about 4563.0699096113. The cubic root of 20821607 is about 275.1089683860.

The spelling of 20821607 in words is "twenty million, eight hundred twenty-one thousand, six hundred seven".