1621246143551 has 2 divisors, whose sum is σ = 1621246143552. Its totient is φ = 1621246143550.

The previous prime is 1621246143533. The next prime is 1621246143571. The reversal of 1621246143551 is 1553416421261.

It is a weak prime.

It is an emirp because it is prime and its reverse (1553416421261) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1621246143551 - 2²⁶ = 1621179034687 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1621246143499 and 1621246143508.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1621246143571) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 810623071775 + 810623071776.

It is an arithmetic number, because the mean of its divisors is an integer number (810623071776).

Almost surely, 2^{1621246143551} is an apocalyptic number.

1621246143551 is a deficient number, since it is larger than the sum of its proper divisors (1).

1621246143551 is an equidigital number, since it uses as much as digits as its factorization.

1621246143551 is an evil number, because the sum of its binary digits is even.

The product of its digits is 172800, while the sum is 41.

The spelling of 1621246143551 in words is "one trillion, six hundred twenty-one billion, two hundred forty-six million, one hundred forty-three thousand, five hundred fifty-one".