21507045 has 32 divisors (see below), whose sum is σ = 39529728. Its totient is φ = 9781248.

The previous prime is 21507007. The next prime is 21507071. The reversal of 21507045 is 54070512.

It is not a de Polignac number, because 21507045 - 2⁶ = 21506981 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 26587 + ... + 27383.

It is an arithmetic number, because the mean of its divisors is an integer number (1235304).

Almost surely, 2^21507045 is an apocalyptic number.

It is an amenable number.

21507045 is a deficient number, since it is larger than the sum of its proper divisors (18022683).

21507045 is a wasteful number, since it uses less digits than its factorization.

21507045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1069.

The product of its (nonzero) digits is 1400, while the sum is 24.

The square root of 21507045 is about 4637.5688674132. The cubic root of 21507045 is about 278.0952565929.

Adding to 21507045 its reverse (54070512), we get a palindrome (75577557).

The spelling of 21507045 in words is "twenty-one million, five hundred seven thousand, forty-five".