1641520356397 has 4 divisors (see below), whose sum is σ = 1668430526236. Its totient is φ = 1614610186560.

The previous prime is 1641520356367. The next prime is 1641520356449. The reversal of 1641520356397 is 7936530251461.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 275681702916 + 1365838653481 = 525054^2 + 1168691^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1641520356397 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1641520356317) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 13455084828 + ... + 13455084949.

It is an arithmetic number, because the mean of its divisors is an integer number (417107631559).

Almost surely, 2^{1641520356397} is an apocalyptic number.

It is an amenable number.

1641520356397 is a deficient number, since it is larger than the sum of its proper divisors (26910169839).

1641520356397 is an equidigital number, since it uses as much as digits as its factorization.

1641520356397 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26910169838.

The product of its (nonzero) digits is 4082400, while the sum is 52.

The spelling of 1641520356397 in words is "one trillion, six hundred forty-one billion, five hundred twenty million, three hundred fifty-six thousand, three hundred ninety-seven".