21305145400 has 96 divisors (see below), whose sum is σ = 61757297280. Its totient is φ = 6640560000.

The previous prime is 21305145373. The next prime is 21305145409. The reversal of 21305145400 is 454150312.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (25).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21305145409) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 676326 + ... + 707125.

It is an arithmetic number, because the mean of its divisors is an integer number (643305180).

Almost surely, 2^21305145400 is an apocalyptic number.

21305145400 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21305145400 is an abundant number, since it is smaller than the sum of its proper divisors (40452151880).

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

21305145400 is a wasteful number, since it uses less digits than its factorization.

21305145400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1383485 (or 1383476 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 25.

Adding to 21305145400 its reverse (454150312), we get a palindrome (21759295712).

The spelling of 21305145400 in words is "twenty-one billion, three hundred five million, one hundred forty-five thousand, four hundred".