21240786570 has 16 divisors (see below), whose sum is σ = 50977887840. Its totient is φ = 5664209744.

The previous prime is 21240786559. The next prime is 21240786571. The reversal of 21240786570 is 7568704212.

It is a super-2 number, since 2×21240786570² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21240786571) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 354013080 + ... + 354013139.

It is an arithmetic number, because the mean of its divisors is an integer number (3186117990).

Almost surely, 2^21240786570 is an apocalyptic number.

21240786570 is an abundant number, since it is smaller than the sum of its proper divisors (29737101270).

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

21240786570 is a wasteful number, since it uses less digits than its factorization.

21240786570 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 708026229.

The product of its (nonzero) digits is 188160, while the sum is 42.

The spelling of 21240786570 in words is "twenty-one billion, two hundred forty million, seven hundred eighty-six thousand, five hundred seventy".