21091204510 has 32 divisors (see below), whose sum is σ = 38097555552. Its totient is φ = 8406894720.

The previous prime is 21091204487. The next prime is 21091204523. The reversal of 21091204510 is 1540219012.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3792652 + ... + 3798208.

It is an arithmetic number, because the mean of its divisors is an integer number (1190548611).

Almost surely, 2^21091204510 is an apocalyptic number.

21091204510 is a deficient number, since it is larger than the sum of its proper divisors (17006351042).

21091204510 is a wasteful number, since it uses less digits than its factorization.

21091204510 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6828.

The product of its (nonzero) digits is 720, while the sum is 25.

The spelling of 21091204510 in words is "twenty-one billion, ninety-one million, two hundred four thousand, five hundred ten".