69972821 has 2 divisors, whose sum is σ = 69972822. Its totient is φ = 69972820.

The previous prime is 69972817. The next prime is 69972827. The reversal of 69972821 is 12827996.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 50268100 + 19704721 = 7090^2 + 4439^2 .

It is a cyclic number.

It is not a de Polignac number, because 69972821 - 2² = 69972817 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (69972827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 34986410 + 34986411.

It is an arithmetic number, because the mean of its divisors is an integer number (34986411).

Almost surely, 2^69972821 is an apocalyptic number.

It is an amenable number.

69972821 is a deficient number, since it is larger than the sum of its proper divisors (1).

69972821 is an equidigital number, since it uses as much as digits as its factorization.

69972821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 108864, while the sum is 44.

The square root of 69972821 is about 8364.9758517284. The cubic root of 69972821 is about 412.0751838316.

The spelling of 69972821 in words is "sixty-nine million, nine hundred seventy-two thousand, eight hundred twenty-one".