147697721 has 2 divisors, whose sum is σ = 147697722. Its totient is φ = 147697720.

The previous prime is 147697691. The next prime is 147697727. The reversal of 147697721 is 127796741.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 140754496 + 6943225 = 11864^2 + 2635^2 .

It is an emirp because it is prime and its reverse (127796741) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-147697721 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (147697727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 73848860 + 73848861.

It is an arithmetic number, because the mean of its divisors is an integer number (73848861).

Almost surely, 2^147697721 is an apocalyptic number.

It is an amenable number.

147697721 is a deficient number, since it is larger than the sum of its proper divisors (1).

147697721 is an equidigital number, since it uses as much as digits as its factorization.

147697721 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 148176, while the sum is 44.

The square root of 147697721 is about 12153.0951201741. The cubic root of 147697721 is about 528.5968831980.

The spelling of 147697721 in words is "one hundred forty-seven million, six hundred ninety-seven thousand, seven hundred twenty-one".