1625340312661 has 4 divisors (see below), whose sum is σ = 1750366490572. Its totient is φ = 1500314134752.

The previous prime is 1625340312647. The next prime is 1625340312667. The reversal of 1625340312661 is 1662130435261.

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 453425810161 + 1171914502500 = 673369^2 + 1082550^2 .

It is a cyclic number.

It is not a de Polignac number, because 1625340312661 - 2²¹ = 1625338215509 is a prime.

It is a super-2 number, since 2×1625340312661² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1625340312667) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 62513088936 + ... + 62513088961.

It is an arithmetic number, because the mean of its divisors is an integer number (437591622643).

Almost surely, 2^{1625340312661} is an apocalyptic number.

It is an amenable number.

1625340312661 is a deficient number, since it is larger than the sum of its proper divisors (125026177911).

1625340312661 is a wasteful number, since it uses less digits than its factorization.

1625340312661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125026177910.

The product of its (nonzero) digits is 155520, while the sum is 40.

The spelling of 1625340312661 in words is "one trillion, six hundred twenty-five billion, three hundred forty million, three hundred twelve thousand, six hundred sixty-one".