19978470 has 48 divisors (see below), whose sum is σ = 52350480. Its totient is φ = 5285952.

The previous prime is 19978457. The next prime is 19978471. The reversal of 19978470 is 7487991.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19978471) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11712 + ... + 13308.

It is an arithmetic number, because the mean of its divisors is an integer number (1090635).

Almost surely, 2^19978470 is an apocalyptic number.

19978470 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 19978470, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26175240).

19978470 is an abundant number, since it is smaller than the sum of its proper divisors (32372010).

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

19978470 is a wasteful number, since it uses less digits than its factorization.

19978470 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1749 (or 1746 counting only the distinct ones).

The product of its (nonzero) digits is 127008, while the sum is 45.

The square root of 19978470 is about 4469.7281796548. The cubic root of 19978470 is about 271.3443243352.

The spelling of 19978470 in words is "nineteen million, nine hundred seventy-eight thousand, four hundred seventy".