99961421 has 6 divisors (see below), whose sum is σ = 116281710. Its totient is φ = 85681176.

The previous prime is 99961361. The next prime is 99961439. The reversal of 99961421 is 12416999.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 58216900 + 41744521 = 7630^2 + 6461^2 .

It is not a de Polignac number, because 99961421 - 2¹⁰ = 99960397 is a prime.

It is a super-3 number, since 3×99961421³ (a number of 25 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99961441) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1019966 + ... + 1020063.

It is an arithmetic number, because the mean of its divisors is an integer number (19380285).

Almost surely, 2^99961421 is an apocalyptic number.

It is an amenable number.

99961421 is a deficient number, since it is larger than the sum of its proper divisors (16320289).

99961421 is a wasteful number, since it uses less digits than its factorization.

99961421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2040043 (or 2040036 counting only the distinct ones).

The product of its digits is 34992, while the sum is 41.

The square root of 99961421 is about 9998.0708639217. The cubic root of 99961421 is about 464.0991863986.

The spelling of 99961421 in words is "ninety-nine million, nine hundred sixty-one thousand, four hundred twenty-one".