21948411 has 16 divisors (see below), whose sum is σ = 31300128. Its totient is φ = 13632000.

The previous prime is 21948397. The next prime is 21948427. The reversal of 21948411 is 11484912.

It is not a de Polignac number, because 21948411 - 2²¹ = 19851259 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21948461) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3021 + ... + 7281.

It is an arithmetic number, because the mean of its divisors is an integer number (1956258).

Almost surely, 2^21948411 is an apocalyptic number.

21948411 is a deficient number, since it is larger than the sum of its proper divisors (9351717).

21948411 is a wasteful number, since it uses less digits than its factorization.

21948411 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4382.

The product of its digits is 2304, while the sum is 30.

The square root of 21948411 is about 4684.9131261956. The cubic root of 21948411 is about 279.9847398146.

It can be divided in two parts, 21948 and 411, that multiplied together give a triangular number (9020628 = T₄₂₄₇).

The spelling of 21948411 in words is "twenty-one million, nine hundred forty-eight thousand, four hundred eleven".