1621066138730 has 32 divisors (see below), whose sum is σ = 3196097954640. Its totient is φ = 589239454720.

The previous prime is 1621066138709. The next prime is 1621066138807. The reversal of 1621066138730 is 378316601261.

It can be written as a sum of positive squares in 8 ways, for example, as 1425805553041 + 195260585689 = 1194071^2 + 441883^2 .

It is a super-3 number, since 3×1621066138730³ (a number of 38 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 164403401 + ... + 164413260.

Almost surely, 2^{1621066138730} is an apocalyptic number.

1621066138730 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1621066138730 is a deficient number, since it is larger than the sum of its proper divisors (1575031815910).

1621066138730 is a wasteful number, since it uses less digits than its factorization.

1621066138730 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 328816714.

The product of its (nonzero) digits is 217728, while the sum is 44.

The spelling of 1621066138730 in words is "one trillion, six hundred twenty-one billion, sixty-six million, one hundred thirty-eight thousand, seven hundred thirty".