78437940 has 48 divisors (see below), whose sum is σ = 251002752. Its totient is φ = 17928576.

The previous prime is 78437939. The next prime is 78437941. The reversal of 78437940 is 4973487.

It is an interprime number because it is at equal distance from previous prime (78437939) and next prime (78437941).

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a junction number, because it is equal to n+sod(n) for n = 78437892 and 78437901.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78437941) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 92959 + ... + 93798.

It is an arithmetic number, because the mean of its divisors is an integer number (5229224).

Almost surely, 2^78437940 is an apocalyptic number.

78437940 is a gapful number since it is divisible by the number (70) formed by its first and last digit.

It is an amenable number.

78437940 is an abundant number, since it is smaller than the sum of its proper divisors (172564812).

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

78437940 is a wasteful number, since it uses less digits than its factorization.

78437940 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 186776 (or 186774 counting only the distinct ones).

The product of its (nonzero) digits is 169344, while the sum is 42.

The square root of 78437940 is about 8856.5196324516. The cubic root of 78437940 is about 428.0640207607.

The spelling of 78437940 in words is "seventy-eight million, four hundred thirty-seven thousand, nine hundred forty".