399526427521 has 8 divisors (see below), whose sum is σ = 434206563560. Its totient is φ = 365410196352.

The previous prime is 399526427519. The next prime is 399526427551. The reversal of 399526427521 is 125724625993.

It can be written as a sum of positive squares in 4 ways, for example, as 65830730625 + 333695696896 = 256575^2 + 577664^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 399526427521 - 2¹ = 399526427519 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (399526427551) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 140974740 + ... + 140977573.

It is an arithmetic number, because the mean of its divisors is an integer number (54275820445).

Almost surely, 2^399526427521 is an apocalyptic number.

It is an amenable number.

399526427521 is a deficient number, since it is larger than the sum of its proper divisors (34680136039).

399526427521 is a wasteful number, since it uses less digits than its factorization.

399526427521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 281952435.

The product of its digits is 8164800, while the sum is 55.

The spelling of 399526427521 in words is "three hundred ninety-nine billion, five hundred twenty-six million, four hundred twenty-seven thousand, five hundred twenty-one".