69642721 has 4 divisors (see below), whose sum is σ = 69678000. Its totient is φ = 69607444.

The previous prime is 69642719. The next prime is 69642763. The reversal of 69642721 is 12724696.

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 a cyclic number.

It is not a de Polignac number, because 69642721 - 2¹ = 69642719 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (69642791) 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, 14491 + ... + 18688.

It is an arithmetic number, because the mean of its divisors is an integer number (17419500).

Almost surely, 2^69642721 is an apocalyptic number.

It is an amenable number.

69642721 is a deficient number, since it is larger than the sum of its proper divisors (35279).

69642721 is a wasteful number, since it uses less digits than its factorization.

69642721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35278.

The product of its digits is 36288, while the sum is 37.

The square root of 69642721 is about 8345.2214470318. The cubic root of 69642721 is about 411.4261676298.

The spelling of 69642721 in words is "sixty-nine million, six hundred forty-two thousand, seven hundred twenty-one".