21621401645146 has 8 divisors (see below), whose sum is σ = 32534411940180. Its totient is φ = 10776597665088.

The previous prime is 21621401645131. The next prime is 21621401645189. The reversal of 21621401645146 is 64154610412612.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 14065582668921 + 7555818976225 = 3750411^2 + 2748785^2 .

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

It is a super-2 number, since 2×21621401645146² (a number of 27 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17051577951 + ... + 17051579218.

Almost surely, 2^{21621401645146} is an apocalyptic number.

21621401645146 is a deficient number, since it is larger than the sum of its proper divisors (10913010295034).

21621401645146 is a wasteful number, since it uses less digits than its factorization.

21621401645146 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34103157488.

The product of its (nonzero) digits is 276480, while the sum is 43.

The spelling of 21621401645146 in words is "twenty-one trillion, six hundred twenty-one billion, four hundred one million, six hundred forty-five thousand, one hundred forty-six".