402540720 has 40 divisors (see below), whose sum is σ = 1247876976. Its totient is φ = 107344128.

The previous prime is 402540709. The next prime is 402540731. The reversal of 402540720 is 27045204.

It is an interprime number because it is at equal distance from previous prime (402540709) and next prime (402540731).

It is a tau number, because it is divible by the number of its divisors (40).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 838387 + ... + 838866.

Almost surely, 2^402540720 is an apocalyptic number.

402540720 is a gapful number since it is divisible by the number (40) formed by its first and last digit.

It is an amenable number.

402540720 is an abundant number, since it is smaller than the sum of its proper divisors (845336256).

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

402540720 is a wasteful number, since it uses less digits than its factorization.

402540720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1677269 (or 1677263 counting only the distinct ones).

The product of its (nonzero) digits is 2240, while the sum is 24.

The square root of 402540720 is about 20063.4174556579. The cubic root of 402540720 is about 738.3630237840.

Adding to 402540720 its reverse (27045204), we get a palindrome (429585924).

The spelling of 402540720 in words is "four hundred two million, five hundred forty thousand, seven hundred twenty".