19421540 has 12 divisors (see below), whose sum is σ = 40785276. Its totient is φ = 7768608.

The previous prime is 19421537. The next prime is 19421543. The reversal of 19421540 is 4512491.

It is an interprime number because it is at equal distance from previous prime (19421537) and next prime (19421543).

It can be written as a sum of positive squares in 2 ways, for example, as 4227136 + 15194404 = 2056^2 + 3898^2 .

It is not an unprimeable number, because it can be changed into a prime (19421543) 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, 485519 + ... + 485558.

It is an arithmetic number, because the mean of its divisors is an integer number (3398773).

Almost surely, 2^19421540 is an apocalyptic number.

19421540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

19421540 is an abundant number, since it is smaller than the sum of its proper divisors (21363736).

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

19421540 is a wasteful number, since it uses less digits than its factorization.

19421540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 971086 (or 971084 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 26.

The square root of 19421540 is about 4406.9876332933. The cubic root of 19421540 is about 268.7991480333.

The spelling of 19421540 in words is "nineteen million, four hundred twenty-one thousand, five hundred forty".