21211556948 has 24 divisors (see below), whose sum is σ = 39355510824. Its totient is φ = 9968768000.

The previous prime is 21211556939. The next prime is 21211556953. The reversal of 21211556948 is 84965511212.

It can be written as a sum of positive squares in 4 ways, for example, as 34904464 + 21176652484 = 5908^2 + 145522^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21211556899 and 21211556908.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 153203 + ... + 256698.

It is an arithmetic number, because the mean of its divisors is an integer number (1639812951).

Almost surely, 2^21211556948 is an apocalyptic number.

It is an amenable number.

21211556948 is a deficient number, since it is larger than the sum of its proper divisors (18143953876).

21211556948 is a wasteful number, since it uses less digits than its factorization.

21211556948 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 410683 (or 410681 counting only the distinct ones).

The product of its digits is 172800, while the sum is 44.

The spelling of 21211556948 in words is "twenty-one billion, two hundred eleven million, five hundred fifty-six thousand, nine hundred forty-eight".