21021214515524 has 12 divisors (see below), whose sum is σ = 37781372034924. Its totient is φ = 10226536791264.

The previous prime is 21021214515467. The next prime is 21021214515533. The reversal of 21021214515524 is 42551541212012.

It can be written as a sum of positive squares in 2 ways, for example, as 7319135052100 + 13702079463424 = 2705390^2 + 3701632^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 71017616459 + ... + 71017616754.

It is an arithmetic number, because the mean of its divisors is an integer number (3148447669577).

Almost surely, 2^{21021214515524} is an apocalyptic number.

It is an amenable number.

21021214515524 is a deficient number, since it is larger than the sum of its proper divisors (16760157519400).

21021214515524 is a wasteful number, since it uses less digits than its factorization.

21021214515524 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142035233254 (or 142035233252 counting only the distinct ones).

The product of its (nonzero) digits is 32000, while the sum is 35.

Adding to 21021214515524 its reverse (42551541212012), we get a palindrome (63572755727536).

The spelling of 21021214515524 in words is "twenty-one trillion, twenty-one billion, two hundred fourteen million, five hundred fifteen thousand, five hundred twenty-four".