661525341645 has 16 divisors (see below), whose sum is σ = 1209646339200. Its totient is φ = 302411584704.

The previous prime is 661525341629. The next prime is 661525341649. The reversal of 661525341645 is 546143525166.

It is a happy number.

It is not a de Polignac number, because 661525341645 - 2⁴ = 661525341629 is a prime.

It is a super-3 number, since 3×661525341645³ (a number of 36 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 661525341594 and 661525341603.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (661525341649) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3150120570 + ... + 3150120779.

It is an arithmetic number, because the mean of its divisors is an integer number (75602896200).

Almost surely, 2^661525341645 is an apocalyptic number.

It is an amenable number.

661525341645 is a deficient number, since it is larger than the sum of its proper divisors (548120997555).

661525341645 is a wasteful number, since it uses less digits than its factorization.

661525341645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6300241364.

The product of its digits is 2592000, while the sum is 48.

The spelling of 661525341645 in words is "six hundred sixty-one billion, five hundred twenty-five million, three hundred forty-one thousand, six hundred forty-five".