21456243402 has 32 divisors (see below), whose sum is σ = 46833626304. Its totient is φ = 6499113600.

The previous prime is 21456243401. The next prime is 21456243407. The reversal of 21456243402 is 20434265412.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is not an unprimeable number, because it can be changed into a prime (21456243401) by changing a digit.

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 in 15 ways as a sum of consecutive naturals, for example, 88878 + ... + 225414.

It is an arithmetic number, because the mean of its divisors is an integer number (1463550822).

Almost surely, 2^21456243402 is an apocalyptic number.

21456243402 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21456243402 is an abundant number, since it is smaller than the sum of its proper divisors (25377382902).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21456243402 is a wasteful number, since it uses less digits than its factorization.

21456243402 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138934.

The product of its (nonzero) digits is 46080, while the sum is 33.

The spelling of 21456243402 in words is "twenty-one billion, four hundred fifty-six million, two hundred forty-three thousand, four hundred two".