21120013402 has 4 divisors (see below), whose sum is σ = 31680020106. Its totient is φ = 10560006700.

The previous prime is 21120013381. The next prime is 21120013471. The reversal of 21120013402 is 20431002112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 15057989521 + 6062023881 = 122711^2 + 77859^2 .

It is a super-2 number, since 2×21120013402² (a number of 21 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 5280003349 + ... + 5280003352.

Almost surely, 2^21120013402 is an apocalyptic number.

21120013402 is a deficient number, since it is larger than the sum of its proper divisors (10560006704).

21120013402 is a wasteful number, since it uses less digits than its factorization.

21120013402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10560006703.

The product of its (nonzero) digits is 96, while the sum is 16.

Adding to 21120013402 its reverse (20431002112), we get a palindrome (41551015514).

The spelling of 21120013402 in words is "twenty-one billion, one hundred twenty million, thirteen thousand, four hundred two".