387928421 has 2 divisors, whose sum is σ = 387928422. Its totient is φ = 387928420.

The previous prime is 387928381. The next prime is 387928439. The reversal of 387928421 is 124829783.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 359519521 + 28408900 = 18961^2 + 5330^2 .

It is a cyclic number.

It is not a de Polignac number, because 387928421 - 2⁶ = 387928357 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (387928441) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 193964210 + 193964211.

It is an arithmetic number, because the mean of its divisors is an integer number (193964211).

Almost surely, 2^387928421 is an apocalyptic number.

It is an amenable number.

387928421 is a deficient number, since it is larger than the sum of its proper divisors (1).

387928421 is an equidigital number, since it uses as much as digits as its factorization.

387928421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 193536, while the sum is 44.

The square root of 387928421 is about 19695.8985832076. The cubic root of 387928421 is about 729.3184487616.

The spelling of 387928421 in words is "three hundred eighty-seven million, nine hundred twenty-eight thousand, four hundred twenty-one".