39747421 has 4 divisors (see below), whose sum is σ = 45425632. Its totient is φ = 34069212.

The previous prime is 39747413. The next prime is 39747431. The reversal of 39747421 is 12474793.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 39747421 - 2³ = 39747413 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (39747431) 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, 2839095 + ... + 2839108.

It is an arithmetic number, because the mean of its divisors is an integer number (11356408).

Almost surely, 2^39747421 is an apocalyptic number.

It is an amenable number.

39747421 is a deficient number, since it is larger than the sum of its proper divisors (5678211).

39747421 is an equidigital number, since it uses as much as digits as its factorization.

39747421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5678210.

The product of its digits is 42336, while the sum is 37.

The square root of 39747421 is about 6304.5555751377. Note that the first 4 decimals coincide. The cubic root of 39747421 is about 341.2738288360.

The spelling of 39747421 in words is "thirty-nine million, seven hundred forty-seven thousand, four hundred twenty-one".