406399987 has 32 divisors (see below), whose sum is σ = 508006400. Its totient is φ = 317260800.

The previous prime is 406399933. The next prime is 406399991. The reversal of 406399987 is 789993604.

It is a cyclic number.

It is not a de Polignac number, because 406399987 - 2¹¹ = 406397939 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (406399927) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 993439 + ... + 993847.

It is an arithmetic number, because the mean of its divisors is an integer number (15875200).

Almost surely, 2^406399987 is an apocalyptic number.

406399987 is a deficient number, since it is larger than the sum of its proper divisors (101606413).

406399987 is a wasteful number, since it uses less digits than its factorization.

406399987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 707.

The product of its (nonzero) digits is 2939328, while the sum is 55.

The square root of 406399987 is about 20159.3647469359. The cubic root of 406399987 is about 740.7151517124.

The spelling of 406399987 in words is "four hundred six million, three hundred ninety-nine thousand, nine hundred eighty-seven".