69145721 has 8 divisors (see below), whose sum is σ = 70998144. Its totient is φ = 67301280.

The previous prime is 69145709. The next prime is 69145729. The reversal of 69145721 is 12754196.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 69145721 - 2¹⁰ = 69144697 is a prime.

It is a super-2 number, since 2×69145721² = 9562261465219682, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (69145729) 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 in 7 ways as a sum of consecutive naturals, for example, 18236 + ... + 21698.

It is an arithmetic number, because the mean of its divisors is an integer number (8874768).

Almost surely, 2^69145721 is an apocalyptic number.

It is an amenable number.

69145721 is a deficient number, since it is larger than the sum of its proper divisors (1852423).

69145721 is a wasteful number, since it uses less digits than its factorization.

69145721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3991.

The product of its digits is 15120, while the sum is 35.

The square root of 69145721 is about 8315.3906101878. The cubic root of 69145721 is about 410.4451263192.

The spelling of 69145721 in words is "sixty-nine million, one hundred forty-five thousand, seven hundred twenty-one".