21012474 has 24 divisors (see below), whose sum is σ = 48886848. Its totient is φ = 6003480.

The previous prime is 21012457. The next prime is 21012503. The reversal of 21012474 is 47421012.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a self number, because there is not a number n which added to its sum of digits gives 21012474.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 35442 + ... + 36029.

It is an arithmetic number, because the mean of its divisors is an integer number (2036952).

Almost surely, 2^21012474 is an apocalyptic number.

21012474 is an abundant number, since it is smaller than the sum of its proper divisors (27874374).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21012474 is a wasteful number, since it uses less digits than its factorization.

21012474 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71490 (or 71483 counting only the distinct ones).

The product of its (nonzero) digits is 448, while the sum is 21.

The square root of 21012474 is about 4583.9365178850. The cubic root of 21012474 is about 275.9470335243.

Adding to 21012474 its reverse (47421012), we get a palindrome (68433486).

The spelling of 21012474 in words is "twenty-one million, twelve thousand, four hundred seventy-four".