21052666657442 has 16 divisors (see below), whose sum is σ = 36090403683840. Its totient is φ = 9022541928288.

The previous prime is 21052666657441. The next prime is 21052666657471. The reversal of 21052666657442 is 24475666625012.

It is a super-2 number, since 2×21052666657442² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21052666657441) 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, 2294159 + ... + 6882477.

It is an arithmetic number, because the mean of its divisors is an integer number (2255650230240).

Almost surely, 2^{21052666657442} is an apocalyptic number.

It is a pronic number, being equal to 4588318×4588319.

21052666657442 is a deficient number, since it is larger than the sum of its proper divisors (15037737026398).

21052666657442 is a wasteful number, since it uses less digits than its factorization.

21052666657442 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4916065.

The product of its (nonzero) digits is 29030400, while the sum is 56.

The spelling of 21052666657442 in words is "twenty-one trillion, fifty-two billion, six hundred sixty-six million, six hundred fifty-seven thousand, four hundred forty-two".