21603003540387 has 32 divisors (see below), whose sum is σ = 29947779133440. Its totient is φ = 13839828065280.

The previous prime is 21603003540367. The next prime is 21603003540389. The reversal of 21603003540387 is 78304530030612.

It is not a de Polignac number, because 21603003540387 - 2²⁶ = 21602936431523 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21603003540389) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 30895539 + ... + 31587027.

It is an arithmetic number, because the mean of its divisors is an integer number (935868097920).

Almost surely, 2^{21603003540387} is an apocalyptic number.

21603003540387 is a deficient number, since it is larger than the sum of its proper divisors (8344775593053).

21603003540387 is a wasteful number, since it uses less digits than its factorization.

21603003540387 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 695003.

The product of its (nonzero) digits is 362880, while the sum is 42.

Adding to 21603003540387 its reverse (78304530030612), we get a palindrome (99907533570999).

The spelling of 21603003540387 in words is "twenty-one trillion, six hundred three billion, three million, five hundred forty thousand, three hundred eighty-seven".