69918021 has 6 divisors (see below), whose sum is σ = 100992710. Its totient is φ = 46612008.

The previous prime is 69918011. The next prime is 69918029. The reversal of 69918021 is 12081996.

It can be written as a sum of positive squares in only one way, i.e., 61449921 + 8468100 = 7839^2 + 2910^2 .

It is not a de Polignac number, because 69918021 - 2¹⁸ = 69655877 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (69918029) 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 5 ways as a sum of consecutive naturals, for example, 3884326 + ... + 3884343.

Almost surely, 2^69918021 is an apocalyptic number.

It is an amenable number.

69918021 is a deficient number, since it is larger than the sum of its proper divisors (31074689).

69918021 is a wasteful number, since it uses less digits than its factorization.

69918021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7768675 (or 7768672 counting only the distinct ones).

The product of its (nonzero) digits is 7776, while the sum is 36.

The square root of 69918021 is about 8361.6996477989. The cubic root of 69918021 is about 411.9675819687.

Subtracting from 69918021 its reverse (12081996), we obtain a square (57836025 = 7605²).

The spelling of 69918021 in words is "sixty-nine million, nine hundred eighteen thousand, twenty-one".