405651640 has 16 divisors (see below), whose sum is σ = 912716280. Its totient is φ = 162260640.

The previous prime is 405651629. The next prime is 405651641. The reversal of 405651640 is 46156504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (405651641) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 5070606 + ... + 5070685.

Almost surely, 2^405651640 is an apocalyptic number.

405651640 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

405651640 is an abundant number, since it is smaller than the sum of its proper divisors (507064640).

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

405651640 is a wasteful number, since it uses less digits than its factorization.

405651640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10141302 (or 10141298 counting only the distinct ones).

The product of its (nonzero) digits is 14400, while the sum is 31.

The square root of 405651640 is about 20140.7954162689. The cubic root of 405651640 is about 740.2602201462.

It can be divided in two parts, 4056 and 51640, that added together give a square (55696 = 236²).

The spelling of 405651640 in words is "four hundred five million, six hundred fifty-one thousand, six hundred forty".