97749991 has 2 divisors, whose sum is σ = 97749992. Its totient is φ = 97749990.

The previous prime is 97749947. The next prime is 97750007. The reversal of 97749991 is 19994779.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 97749991 - 2¹³ = 97741799 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (97749901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 48874995 + 48874996.

It is an arithmetic number, because the mean of its divisors is an integer number (48874996).

Almost surely, 2^97749991 is an apocalyptic number.

97749991 is a deficient number, since it is larger than the sum of its proper divisors (1).

97749991 is an equidigital number, since it uses as much as digits as its factorization.

97749991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1285956, while the sum is 55.

The square root of 97749991 is about 9886.8595114930. The cubic root of 97749991 is about 460.6512373219.

The spelling of 97749991 in words is "ninety-seven million, seven hundred forty-nine thousand, nine hundred ninety-one".