1615951982401 has 3 divisors (see below), whose sum is σ = 1615953253603. Its totient is φ = 1615950711200.

The previous prime is 1615951982399. The next prime is 1615951982453. The reversal of 1615951982401 is 1042891595161.

The square root of 1615951982401 is 1271201.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in only one way, i.e., 1370887380801 + 245064601600 = 1170849^2 + 495040^2 .

It is not a de Polignac number, because 1615951982401 - 2¹ = 1615951982399 is a prime.

It is a super-2 number, since 2×1615951982401² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1615951982461) 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 2 ways as a sum of consecutive naturals, for example, 635601 + ... + 1906801.

Almost surely, 2^{1615951982401} is an apocalyptic number.

1615951982401 is the 1271201-st square number.

1615951982401 is the 635601-st centered octagonal number.

It is an amenable number.

1615951982401 is a deficient number, since it is larger than the sum of its proper divisors (1271202).

1615951982401 is an frugal number, since it uses more digits than its factorization.

1615951982401 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2542402 (or 1271201 counting only the distinct ones).

The product of its (nonzero) digits is 777600, while the sum is 52.

The spelling of 1615951982401 in words is "one trillion, six hundred fifteen billion, nine hundred fifty-one million, nine hundred eighty-two thousand, four hundred one".