97821839 has 2 divisors, whose sum is σ = 97821840. Its totient is φ = 97821838.

The previous prime is 97821817. The next prime is 97821869. The reversal of 97821839 is 93812879.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 97821839 - 2⁸ = 97821583 is a prime.

It is a super-2 number, since 2×97821839² = 19138224370683842, which contains 22 as substring.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 97821793 and 97821802.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (97821869) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 48910919 + 48910920.

It is an arithmetic number, because the mean of its divisors is an integer number (48910920).

Almost surely, 2^97821839 is an apocalyptic number.

97821839 is a deficient number, since it is larger than the sum of its proper divisors (1).

97821839 is an equidigital number, since it uses as much as digits as its factorization.

97821839 is an evil number, because the sum of its binary digits is even.

The product of its digits is 217728, while the sum is 47.

The square root of 97821839 is about 9890.4923537709. The cubic root of 97821839 is about 460.7640719938.

The spelling of 97821839 in words is "ninety-seven million, eight hundred twenty-one thousand, eight hundred thirty-nine".