215481540 has 24 divisors (see below), whose sum is σ = 603348480. Its totient is φ = 57461728.

The previous prime is 215481533. The next prime is 215481547. The reversal of 215481540 is 45184512.

It is an interprime number because it is at equal distance from previous prime (215481533) and next prime (215481547).

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 215481498 and 215481507.

It is not an unprimeable number, because it can be changed into a prime (215481547) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1795620 + ... + 1795739.

It is an arithmetic number, because the mean of its divisors is an integer number (25139520).

Almost surely, 2^215481540 is an apocalyptic number.

215481540 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

215481540 is an abundant number, since it is smaller than the sum of its proper divisors (387866940).

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

215481540 is a wasteful number, since it uses less digits than its factorization.

215481540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3591371 (or 3591369 counting only the distinct ones).

The product of its (nonzero) digits is 6400, while the sum is 30.

The square root of 215481540 is about 14679.2894923426. The cubic root of 215481540 is about 599.5195598426.

The spelling of 215481540 in words is "two hundred fifteen million, four hundred eighty-one thousand, five hundred forty".