29981421 has 20 divisors (see below), whose sum is σ = 47423772. Its totient is φ = 18811008.

The previous prime is 29981407. The next prime is 29981423. The reversal of 29981421 is 12418992.

It can be written as a sum of positive squares in 2 ways, for example, as 13286025 + 16695396 = 3645^2 + 4086^2 .

It is not a de Polignac number, because 29981421 - 2¹⁹ = 29457133 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (29981423) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 9510 + ... + 12263.

Almost surely, 2^29981421 is an apocalyptic number.

It is an amenable number.

29981421 is a deficient number, since it is larger than the sum of its proper divisors (17442351).

29981421 is a wasteful number, since it uses less digits than its factorization.

29981421 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21802 (or 21793 counting only the distinct ones).

The product of its digits is 10368, while the sum is 36.

The square root of 29981421 is about 5475.5292894843. The cubic root of 29981421 is about 310.6590937131.

The spelling of 29981421 in words is "twenty-nine million, nine hundred eighty-one thousand, four hundred twenty-one".