1015641251621 has 2 divisors, whose sum is σ = 1015641251622. Its totient is φ = 1015641251620.

The previous prime is 1015641251531. The next prime is 1015641251627. The reversal of 1015641251621 is 1261521465101.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 681772233025 + 333869018596 = 825695^2 + 577814^2 .

It is an emirp because it is prime and its reverse (1261521465101) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1015641251621 - 2²² = 1015637057317 is a prime.

It is a super-3 number, since 3×1015641251621³ (a number of 37 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1015641251627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 507820625810 + 507820625811.

It is an arithmetic number, because the mean of its divisors is an integer number (507820625811).

Almost surely, 2^{1015641251621} is an apocalyptic number.

It is an amenable number.

1015641251621 is a deficient number, since it is larger than the sum of its proper divisors (1).

1015641251621 is an equidigital number, since it uses as much as digits as its factorization.

1015641251621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 14400, while the sum is 35.

The spelling of 1015641251621 in words is "one trillion, fifteen billion, six hundred forty-one million, two hundred fifty-one thousand, six hundred twenty-one".