1021378881601 has 8 divisors (see below), whose sum is σ = 1112305438440. Its totient is φ = 932217889152.

The previous prime is 1021378881571. The next prime is 1021378881631. The reversal of 1021378881601 is 1061888731201.

It is an interprime number because it is at equal distance from previous prime (1021378881571) and next prime (1021378881631).

It can be written as a sum of positive squares in 4 ways, for example, as 23425833025 + 997953048576 = 153055^2 + 998976^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 1021378881601 - 2³⁵ = 987019143233 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1021378881631) 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, 441389890 + ... + 441392203.

It is an arithmetic number, because the mean of its divisors is an integer number (139038179805).

Almost surely, 2^{1021378881601} is an apocalyptic number.

It is an amenable number.

1021378881601 is a deficient number, since it is larger than the sum of its proper divisors (90926556839).

1021378881601 is an equidigital number, since it uses as much as digits as its factorization.

1021378881601 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 882782195.

The product of its (nonzero) digits is 129024, while the sum is 46.

The spelling of 1021378881601 in words is "one trillion, twenty-one billion, three hundred seventy-eight million, eight hundred eighty-one thousand, six hundred one".