21250640265 has 8 divisors (see below), whose sum is σ = 34001024448. Its totient is φ = 11333674800.

The previous prime is 21250640251. The next prime is 21250640287. The reversal of 21250640265 is 56204605212.

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

It is not a de Polignac number, because 21250640265 - 2⁴ = 21250640249 is a prime.

It is a Curzon 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, 708354661 + ... + 708354690.

It is an arithmetic number, because the mean of its divisors is an integer number (4250128056).

Almost surely, 2^21250640265 is an apocalyptic number.

It is an amenable number.

21250640265 is a deficient number, since it is larger than the sum of its proper divisors (12750384183).

21250640265 is a wasteful number, since it uses less digits than its factorization.

21250640265 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1416709359.

The product of its (nonzero) digits is 28800, while the sum is 33.

The spelling of 21250640265 in words is "twenty-one billion, two hundred fifty million, six hundred forty thousand, two hundred sixty-five".