21513152446 has 16 divisors (see below), whose sum is σ = 32803211520. Its totient is φ = 10580014720.

The previous prime is 21513152443. The next prime is 21513152449. The reversal of 21513152446 is 64425131512.

It is an interprime number because it is at equal distance from previous prime (21513152443) and next prime (21513152449).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21513152443) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 282391 + ... + 350386.

It is an arithmetic number, because the mean of its divisors is an integer number (2050200720).

Almost surely, 2^21513152446 is an apocalyptic number.

21513152446 is a deficient number, since it is larger than the sum of its proper divisors (11290059074).

21513152446 is a wasteful number, since it uses less digits than its factorization.

21513152446 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 633059.

The product of its digits is 28800, while the sum is 34.

Adding to 21513152446 its reverse (64425131512), we get a palindrome (85938283958).

The spelling of 21513152446 in words is "twenty-one billion, five hundred thirteen million, one hundred fifty-two thousand, four hundred forty-six".