21090603900 has 36 divisors (see below), whose sum is σ = 61022148152. Its totient is φ = 5624160960.

The previous prime is 21090603883. The next prime is 21090603901. The reversal of 21090603900 is 930609012.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21090603901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 35150707 + ... + 35151306.

Almost surely, 2^21090603900 is an apocalyptic number.

21090603900 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21090603900 is an abundant number, since it is smaller than the sum of its proper divisors (39931544252).

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

21090603900 is a wasteful number, since it uses less digits than its factorization.

21090603900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70302030 (or 70302023 counting only the distinct ones).

The product of its (nonzero) digits is 2916, while the sum is 30.

The spelling of 21090603900 in words is "twenty-one billion, ninety million, six hundred three thousand, nine hundred".