381721725 has 108 divisors (see below), whose sum is σ = 859299168. Its totient is φ = 158558400.

The previous prime is 381721709. The next prime is 381721729. The reversal of 381721725 is 527127183.

It is not a de Polignac number, because 381721725 - 2⁴ = 381721709 is a prime.

It is a super-2 number, since 2×381721725² = 291422950673951250, which contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 381721725.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (381721729) by changing a digit.

It is a polite number, since it can be written in 107 ways as a sum of consecutive naturals, for example, 189574 + ... + 191576.

Almost surely, 2^381721725 is an apocalyptic number.

381721725 is a gapful number since it is divisible by the number (35) formed by its first and last digit.

It is an amenable number.

381721725 is an abundant number, since it is smaller than the sum of its proper divisors (477577443).

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

381721725 is a wasteful number, since it uses less digits than its factorization.

381721725 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2048 (or 2029 counting only the distinct ones).

The product of its digits is 23520, while the sum is 36.

The square root of 381721725 is about 19537.7000949446. The cubic root of 381721725 is about 725.4079194710.

The spelling of 381721725 in words is "three hundred eighty-one million, seven hundred twenty-one thousand, seven hundred twenty-five".