661929125 has 64 divisors (see below), whose sum is σ = 1022112000. Its totient is φ = 420768000.

The previous prime is 661929109. The next prime is 661929131. The reversal of 661929125 is 521929166.

It is not a de Polignac number, because 661929125 - 2⁴ = 661929109 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 338651 + ... + 340599.

It is an arithmetic number, because the mean of its divisors is an integer number (15970500).

Almost surely, 2^661929125 is an apocalyptic number.

661929125 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

661929125 is a deficient number, since it is larger than the sum of its proper divisors (360182875).

661929125 is a wasteful number, since it uses less digits than its factorization.

661929125 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2007 (or 1997 counting only the distinct ones).

The product of its digits is 58320, while the sum is 41.

The square root of 661929125 is about 25727.9833061202. The cubic root of 661929125 is about 871.5062316412.

Adding to 661929125 its sum of digits (41), we get a palindrome (661929166).

The spelling of 661929125 in words is "six hundred sixty-one million, nine hundred twenty-nine thousand, one hundred twenty-five".