1545021621 has 40 divisors (see below), whose sum is σ = 2711511264. Its totient is φ = 864341280.

The previous prime is 1545021601. The next prime is 1545021671. The reversal of 1545021621 is 1261205451.

1545021621 is a `hidden beast` number, since 15 + 4 + 5 + 0 + 21 + 621 = 666.

It is not a de Polignac number, because 1545021621 - 2⁵ = 1545021589 is a prime.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1545021601) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 55111 + ... + 78276.

Almost surely, 2^1545021621 is an apocalyptic number.

1545021621 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1545021621 is a deficient number, since it is larger than the sum of its proper divisors (1166489643).

1545021621 is a wasteful number, since it uses less digits than its factorization.

1545021621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 133423 (or 133414 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 27.

The square root of 1545021621 is about 39306.7630440361. The cubic root of 1545021621 is about 1156.0541766993.

The spelling of 1545021621 in words is "one billion, five hundred forty-five million, twenty-one thousand, six hundred twenty-one".