21203000155 has 8 divisors (see below), whose sum is σ = 25801961184. Its totient is φ = 16723492800.

The previous prime is 21203000123. The next prime is 21203000197. The reversal of 21203000155 is 55100030212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21203000155 - 2⁵ = 21203000123 is a prime.

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, 29863026 + ... + 29863735.

It is an arithmetic number, because the mean of its divisors is an integer number (3225245148).

Almost surely, 2^21203000155 is an apocalyptic number.

21203000155 is a deficient number, since it is larger than the sum of its proper divisors (4598961029).

21203000155 is an equidigital number, since it uses as much as digits as its factorization.

21203000155 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59726837.

The product of its (nonzero) digits is 300, while the sum is 19.

Adding to 21203000155 its reverse (55100030212), we get a palindrome (76303030367).

The spelling of 21203000155 in words is "twenty-one billion, two hundred three million, one hundred fifty-five", and thus it is an aban number.