1387921725 has 36 divisors (see below), whose sum is σ = 2488437952. Its totient is φ = 739476000.

The previous prime is 1387921721. The next prime is 1387921741. The reversal of 1387921725 is 5271297831.

It is not a de Polignac number, because 1387921725 - 2² = 1387921721 is a prime.

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

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1387921721) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 274470 + ... + 279480.

Almost surely, 2^1387921725 is an apocalyptic number.

1387921725 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1387921725 is a deficient number, since it is larger than the sum of its proper divisors (1100516227).

1387921725 is a wasteful number, since it uses less digits than its factorization.

1387921725 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6258 (or 6250 counting only the distinct ones).

The product of its digits is 211680, while the sum is 45.

The square root of 1387921725 is about 37254.8215000421. The cubic root of 1387921725 is about 1115.4625427825.

The spelling of 1387921725 in words is "one billion, three hundred eighty-seven million, nine hundred twenty-one thousand, seven hundred twenty-five".