99121401 has 32 divisors (see below), whose sum is σ = 151299840. Its totient is φ = 64910160.

The previous prime is 99121387. The next prime is 99121411. The reversal of 99121401 is 10412199.

It is not a de Polignac number, because 99121401 - 2⁵ = 99121369 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (99121411) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 133036 + ... + 133778.

It is an arithmetic number, because the mean of its divisors is an integer number (4728120).

Almost surely, 2^99121401 is an apocalyptic number.

It is an amenable number.

99121401 is a deficient number, since it is larger than the sum of its proper divisors (52178439).

99121401 is an frugal number, since it uses more digits than its factorization.

With its predecessor (99121400) it forms a Ruth-Aaron pair, since the sum of their prime factors is the same (825).

99121401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 825 (or 807 counting only the distinct ones).

The product of its (nonzero) digits is 648, while the sum is 27.

The square root of 99121401 is about 9955.9731317436. The cubic root of 99121401 is about 462.7955175892.

The spelling of 99121401 in words is "ninety-nine million, one hundred twenty-one thousand, four hundred one".