69696721 has 4 divisors (see below), whose sum is σ = 69714432. Its totient is φ = 69679012.

The previous prime is 69696713. The next prime is 69696727. The reversal of 69696721 is 12769696.

69696721 is a nontrivial binomial coefficient, being equal to C(11807, 2).

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 69696721 - 2³ = 69696713 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (69696727) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1 + ... + 11806.

It is an arithmetic number, because the mean of its divisors is an integer number (17428608).

Almost surely, 2^69696721 is an apocalyptic number.

69696721 is the 11806-th triangular number.

69696721 is the 3936-th centered nonagonal number.

It is an amenable number.

69696721 is a deficient number, since it is larger than the sum of its proper divisors (17711).

69696721 is a wasteful number, since it uses less digits than its factorization.

69696721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17710.

The product of its digits is 244944, while the sum is 46.

The square root of 69696721 is about 8348.4562045926. The cubic root of 69696721 is about 411.5324782054.

Subtracting from 69696721 its reverse (12769696), we obtain a square (56927025 = 7545²).

It can be divided in two parts, 69 and 696721, that added together give a triangular number (696790 = T₁₁₈₀).

The spelling of 69696721 in words is "sixty-nine million, six hundred ninety-six thousand, seven hundred twenty-one".