21315045 has 32 divisors (see below), whose sum is σ = 35094528. Its totient is φ = 11043648.

The previous prime is 21315037. The next prime is 21315053. The reversal of 21315045 is 54051312.

It is an interprime number because it is at equal distance from previous prime (21315037) and next prime (21315053).

It is not a de Polignac number, because 21315045 - 2³ = 21315037 is a prime.

It is a super-2 number, since 2×21315045² = 908662286704050, which contains 22 as substring.

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, 127552 + ... + 127718.

It is an arithmetic number, because the mean of its divisors is an integer number (1096704).

Almost surely, 2^21315045 is an apocalyptic number.

It is an amenable number.

21315045 is a deficient number, since it is larger than the sum of its proper divisors (13779483).

21315045 is a wasteful number, since it uses less digits than its factorization.

21315045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 369.

The product of its (nonzero) digits is 600, while the sum is 21.

The square root of 21315045 is about 4616.8219588804. The cubic root of 21315045 is about 277.2652344444.

Adding to 21315045 its reverse (54051312), we get a palindrome (75366357).

The spelling of 21315045 in words is "twenty-one million, three hundred fifteen thousand, forty-five".