21621401650734 has 16 divisors (see below), whose sum is σ = 44297505821520. Its totient is φ = 7031350130240.

The previous prime is 21621401650699. The next prime is 21621401650741. The reversal of 21621401650734 is 43705610412612.

It is a Curzon number.

It is a congruent number.

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, 43945938069 + ... + 43945938560.

It is an arithmetic number, because the mean of its divisors is an integer number (2768594113845).

Almost surely, 2^{21621401650734} is an apocalyptic number.

21621401650734 is an abundant number, since it is smaller than the sum of its proper divisors (22676104170786).

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

21621401650734 is a wasteful number, since it uses less digits than its factorization.

21621401650734 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 87891876675.

The product of its (nonzero) digits is 241920, while the sum is 42.

The spelling of 21621401650734 in words is "twenty-one trillion, six hundred twenty-one billion, four hundred one million, six hundred fifty thousand, seven hundred thirty-four".