21152345 has 16 divisors (see below), whose sum is σ = 26685120. Its totient is φ = 16075584.

The previous prime is 21152333. The next prime is 21152381. The reversal of 21152345 is 54325112.

It is a cyclic number.

It is not a de Polignac number, because 21152345 - 2¹² = 21148249 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21152345.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6626 + ... + 9284.

It is an arithmetic number, because the mean of its divisors is an integer number (1667820).

Almost surely, 2^21152345 is an apocalyptic number.

It is an amenable number.

21152345 is a deficient number, since it is larger than the sum of its proper divisors (5532775).

21152345 is a wasteful number, since it uses less digits than its factorization.

21152345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2744.

The product of its digits is 1200, while the sum is 23.

The square root of 21152345 is about 4599.1678595155. The cubic root of 21152345 is about 276.5579668467.

Adding to 21152345 its reverse (54325112), we get a palindrome (75477457).

It can be divided in two parts, 2115 and 2345, that multiplied together give a triangular number (4959675 = T₃₁₄₉).

The spelling of 21152345 in words is "twenty-one million, one hundred fifty-two thousand, three hundred forty-five".