21002051415 has 16 divisors (see below), whose sum is σ = 33609139200. Its totient is φ = 11199141792.

The previous prime is 21002051381. The next prime is 21002051419. The reversal of 21002051415 is 51415020012.

It is not a de Polignac number, because 21002051415 - 2⁸ = 21002051159 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21002051391 and 21002051400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21002051419) 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, 30895 + ... + 207264.

It is an arithmetic number, because the mean of its divisors is an integer number (2100571200).

Almost surely, 2^21002051415 is an apocalyptic number.

21002051415 is a deficient number, since it is larger than the sum of its proper divisors (12607087785).

21002051415 is a wasteful number, since it uses less digits than its factorization.

21002051415 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 244046.

The product of its (nonzero) digits is 400, while the sum is 21.

Adding to 21002051415 its reverse (51415020012), we get a palindrome (72417071427).

The spelling of 21002051415 in words is "twenty-one billion, two million, fifty-one thousand, four hundred fifteen".