42921649 has 4 divisors (see below), whose sum is σ = 43185136. Its totient is φ = 42658164.

The previous prime is 42921643. The next prime is 42921677. The reversal of 42921649 is 94612924.

It is a happy number.

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 42921649 - 2¹⁹ = 42397361 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (42921643) 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, 131499 + ... + 131824.

It is an arithmetic number, because the mean of its divisors is an integer number (10796284).

Almost surely, 2^42921649 is an apocalyptic number.

It is an amenable number.

42921649 is a deficient number, since it is larger than the sum of its proper divisors (263487).

42921649 is a wasteful number, since it uses less digits than its factorization.

42921649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 263486.

The product of its digits is 31104, while the sum is 37.

The square root of 42921649 is about 6551.4615926524. The cubic root of 42921649 is about 350.1268900458.

The spelling of 42921649 in words is "forty-two million, nine hundred twenty-one thousand, six hundred forty-nine".