69136821 has 20 divisors (see below), whose sum is σ = 111224652. Its totient is φ = 42545088.

The previous prime is 69136817. The next prime is 69136829. The reversal of 69136821 is 12863196.

It can be written as a sum of positive squares in 2 ways, for example, as 45077796 + 24059025 = 6714^2 + 4905^2 .

It is not a de Polignac number, because 69136821 - 2² = 69136817 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (69136829) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 31776 + ... + 33881.

Almost surely, 2^69136821 is an apocalyptic number.

It is an amenable number.

69136821 is a deficient number, since it is larger than the sum of its proper divisors (42087831).

69136821 is a wasteful number, since it uses less digits than its factorization.

69136821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65682 (or 65673 counting only the distinct ones).

The product of its digits is 15552, while the sum is 36.

The square root of 69136821 is about 8314.8554407157. The cubic root of 69136821 is about 410.4275155964.

The spelling of 69136821 in words is "sixty-nine million, one hundred thirty-six thousand, eight hundred twenty-one".