21415145554 has 12 divisors (see below), whose sum is σ = 35308442862. Its totient is φ = 9734156960.

The previous prime is 21415145491. The next prime is 21415145561. The reversal of 21415145554 is 45554151412.

It can be written as a sum of positive squares in only one way, i.e., 11251481329 + 10163664225 = 106073^2 + 100815^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 44245927 + ... + 44246410.

Almost surely, 2^21415145554 is an apocalyptic number.

21415145554 is a deficient number, since it is larger than the sum of its proper divisors (13893297308).

21415145554 is a wasteful number, since it uses less digits than its factorization.

21415145554 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88492361 (or 88492350 counting only the distinct ones).

The product of its digits is 80000, while the sum is 37.

Adding to 21415145554 its reverse (45554151412), we get a palindrome (66969296966).

The spelling of 21415145554 in words is "twenty-one billion, four hundred fifteen million, one hundred forty-five thousand, five hundred fifty-four".