21012153 has 16 divisors (see below), whose sum is σ = 30689280. Its totient is φ = 12728576.

The previous prime is 21012151. The next prime is 21012161. The reversal of 21012153 is 35121012.

It is a cyclic number.

It is not a de Polignac number, because 21012153 - 2¹ = 21012151 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21012151) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5625 + ... + 8582.

It is an arithmetic number, because the mean of its divisors is an integer number (1918080).

Almost surely, 2^21012153 is an apocalyptic number.

It is an amenable number.

21012153 is a deficient number, since it is larger than the sum of its proper divisors (9677127).

21012153 is a wasteful number, since it uses less digits than its factorization.

21012153 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14256.

The product of its (nonzero) digits is 60, while the sum is 15.

The square root of 21012153 is about 4583.9015041774. The cubic root of 21012153 is about 275.9456283360.

Adding to 21012153 its reverse (35121012), we get a palindrome (56133165).

The spelling of 21012153 in words is "twenty-one million, twelve thousand, one hundred fifty-three".