1729921725 has 144 divisors (see below), whose sum is σ = 3729642240. Its totient is φ = 783820800.

The previous prime is 1729921667. The next prime is 1729921727. The reversal of 1729921725 is 5271299271.

1729921725 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 1729921725 - 2¹⁴ = 1729905341 is a prime.

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 (1729921727) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 6383340 + ... + 6383610.

Almost surely, 2^1729921725 is an apocalyptic number.

1729921725 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1729921725 is an abundant number, since it is smaller than the sum of its proper divisors (1999720515).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1729921725 is a wasteful number, since it uses less digits than its factorization.

1729921725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 497 (or 479 counting only the distinct ones).

The product of its digits is 158760, while the sum is 45.

The square root of 1729921725 is about 41592.3277179818. The cubic root of 1729921725 is about 1200.4446789468. Note that the first 3 decimals are identical.

The spelling of 1729921725 in words is "one billion, seven hundred twenty-nine million, nine hundred twenty-one thousand, seven hundred twenty-five".