199690120125 has 60 divisors (see below), whose sum is σ = 372365398548. Its totient is φ = 106477416000.

The previous prime is 199690120121. The next prime is 199690120127. The reversal of 199690120125 is 521021096991.

It is a powerful number, because all its prime factors have an exponent greater than 1 and also an Achilles number because it is not a perfect power.

It can be written as a sum of positive squares in 6 ways, for example, as 86941240164 + 112748879961 = 294858^2 + 335781^2 .

It is not a de Polignac number, because 199690120125 - 2² = 199690120121 is a prime.

It is a super-2 number, since 2×199690120125² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (199690120121) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 44962905 + ... + 44967345.

Almost surely, 2^199690120125 is an apocalyptic number.

199690120125 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

199690120125 is a deficient number, since it is larger than the sum of its proper divisors (172675278423).

199690120125 is an frugal number, since it uses more digits than its factorization.

199690120125 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8909 (or 4449 counting only the distinct ones).

The product of its (nonzero) digits is 87480, while the sum is 45.

Multiplying 199690120125 by its sum of digits (45), we get a square (8986055405625 = 2997675²).

199690120125 divided by its sum of digits (45) gives a square (4437558225 = 66615²).

The spelling of 199690120125 in words is "one hundred ninety-nine billion, six hundred ninety million, one hundred twenty thousand, one hundred twenty-five".